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Childbirth is a defining moment in anyone's life, and it occurs 140 million times per year. Largely a physiologic process, parturition does come with risks; one mother dies every two minutes. These deaths occur mostly among healthy women, and many are considered preventable. For each death, 20 to 30 mothers experience complications that compromise their short- and long-term health. The risk of birth extends to the newborn, and, in 2020, 2.4 million neonates died, 25% in the first day of life. Hence, intrapartum care is an important priority for society. The American Journal of Obstetrics & Gynecology has devoted two special Supplements in 2023 and 2024 to the clinical aspects of labor at term. This article describes the content of the Supplements and highlights new developments in the induction of labor (a comparison of methods, definition of failed induction, new pharmacologic agents), management of the second stage, the value of intrapartum sonography, new concepts on soft tissue dystocia, optimal care during the third stage, and common complications that account for maternal death, such as infection, hemorrhage, and uterine rupture. All articles are available to subscribers and non-subscribers and have supporting video content to enhance dissemination and improve intrapartum care. Our hope is that no mother suffers because of lack of information. [ABSTRACT FROM AUTHOR]

The first feasibility study of the OdonAssist inflatable device for use in clinically indicated assisted vaginal birth reported a success rate of 48% with no significant safety concerns. Additional studies exploring the device performance in other clinical settings are warranted before definitive conclusions can be drawn about its safety and efficacy in current practice. This study aimed to investigate the safety and efficacy of the OdonAssist before conducting a randomized controlled trial. This was an open-label, nonrandomized study of 104 women with a clinically indicated assisted vaginal birth using the OdonAssist at the Besancon University Hospital, France. Data, including those of a nested cohort group of women who had an assisted vaginal birth using vacuum or spatulas because a trained OdonAssist device operator was not available at the time of delivery, were collected. The primary outcome measure was the proportion of successful assisted vaginal births using the OdonAssist. Neonatal outcome data were reviewed at days 1 and 28, and maternal outcomes were investigated up to day 90. Between December 2019 and May 2021, 2191 pregnant women were approached, and 83% (1636/1973) of them consented to participate in the study. Among them, 10.7% (176/1636) required an assisted vaginal birth owing to a vertex presentation at +1 and below. The OdonAssist was used in 59% of births (104/176), and 41.1% (72/176) of the participants were included in the nested cohort group. The rate of successful assisted vaginal births using the OdonAssist was 88.5% (92/104). No emergency cesarean deliveries were performed in the OdonAssist group. There were no serious adverse maternal or neonatal reactions related to the use of the device. The rate of third- and fourth-degree perineal tears with the OdonAssist was 3.8% (4/104). The maternal perception ratings of the birth experience with the OdonAssist (collected on days 1, 7, and 28 using a 15-point scale) were high. In addition, the operators reported a positive perception of the device, with ease of use across the different steps of the procedure. One single technique was used for all vertex fetal head positions. The OdonAssist is a safe and effective alternative to other current devices for assisted vaginal births. The high acceptance rate (83%) among pregnant women and the high rate of successful assisted vaginal births using the OdonAssist confirm the feasibility of a future randomized controlled trial. [ABSTRACT FROM AUTHOR]

Oxytocin is a reproductive hormone implicated in the process of parturition and widely used during labor. Oxytocin is produced within the supraoptic nucleus and paraventricular nucleus of the hypothalamus and released from the posterior pituitary lobe into the circulation. Oxytocin is released in pulses with increasing frequency and amplitude in the first and second stages of labor, with a few pulses released in the third stage of labor. During labor, the fetus exerts pressure on the cervix of the uterus, which activates a feedforward reflex—the Ferguson reflex—which releases oxytocin. When myometrial contractions activate sympathetic nerves, it decreases oxytocin release. When oxytocin binds to specific myometrial oxytocin receptors, it induces myometrial contractions. High levels of circulating estrogen at term make the receptors more sensitive. In addition, oxytocin stimulates prostaglandin synthesis and release in the decidua and chorioamniotic membranes by activating a specific type of oxytocin receptor. Prostaglandins contribute to cervical ripening and uterine contractility in labor. The oxytocin system in the brain has been implicated in decreasing maternal levels of fear, pain, and stress, and oxytocin release and function during labor are stimulated by a social support. Moreover, studies suggest, but have not yet proven, that labor may be associated with long-term, behavioral and physiological adaptations in the mother and infant, possibly involving epigenetic modulation of oxytocin production and release and the oxytocin receptor. In addition, infusions of synthetic oxytocin are used to induce and augment labor. Oxytocin may be administered according to different dose regimens at increasing rates from 1 to 3 mIU/min to a maximal rate of 36 mIU/min at 15- to 40-minute intervals. The total amount of synthetic oxytocin given during labor can be 5 to 10 IU, but lower and higher amounts of oxytocin may also be given. High-dose infusions of oxytocin may shorten the duration of labor by up to 2 hours compared with no infusion of oxytocin; however, it does not lower the frequency of cesarean delivery. When synthetic oxytocin is administered, the plasma concentration of oxytocin increases in a dose-dependent way: at infusion rates of 20 to 30 mIU/min, plasma oxytocin concentration increases approximately 2- to 3-fold above the basal level. Synthetic oxytocin administered at recommended dose levels is not likely to cross the placenta or maternal blood-brain barrier. Synthetic oxytocin should be administered with caution as high levels may induce tachystole and uterine overstimulation, with potentially negative consequences for the fetus and possibly the mother. Of note, 5 to 10 IU of synthetic oxytocin is often routinely given as an intravenous or intramuscular bolus administration after delivery to induce uterine contractility, which, in turn, induces uterine separation of the placenta and prevents postpartum hemorrhage. Furthermore, it promotes the expulsion of the placenta. [ABSTRACT FROM AUTHOR]

Smaller pelvic floor dimensions seem to have been an evolutionary need to provide adequate support for the pelvic organs and the fetal head. Pelvic floor dimension and shape contributed to the complexity of human birth. Maternal pushing associated with pelvic floor muscle relaxation is key to vaginal birth. Using transperineal ultrasound, pelvic floor dimensions can be objectively measured in both static and dynamic conditions, such as pelvic floor muscle contraction and pushing. Several studies have evaluated the role of the pelvic floor in labor outcomes. Smaller levator hiatal dimensions seem to be associated with a longer duration of the second stage of labor and a higher risk of cesarean and operative deliveries. Furthermore, smaller levator hiatal dimensions are associated with a higher fetal head station at term of pregnancy, as assessed by transperineal ultrasound. With maternal pushing, most women can relax their pelvic floor, thus increasing their pelvic floor dimensions. Some women contract rather than relax their pelvic floor muscles under pushing, which is associated with a reduction in the anteroposterior diameter of the levator hiatus. This phenomenon is called levator ani muscle coactivation. Coactivation in nulliparous women at term of pregnancy before the onset of labor is associated with a higher fetal head station at term of pregnancy and a longer duration of the second stage of labor. In addition, levator ani muscle coactivation in nulliparous women undergoing induction of labor is associated with a longer duration of the active second stage of labor. Whether we can improve maternal pelvic floor relaxation with consequent improvement in labor outcomes remains a matter of debate. Maternal education, physiotherapy, and visual feedback are promising interventions. In particular, ultrasound visual feedback before the onset of labor can help women increase their levator hiatal dimensions and correct levator ani muscle coactivation in some cases. Ultrasound visual feedback in the second stage of labor was found to help women push more efficiently, thus obtaining a lower fetal head station at ultrasound and a shorter duration of the second stage of labor. The available evidence on the role of any intervention aimed to aid women to better relax their pelvic floor remains limited, and more studies are needed before considering its routine clinical application. [ABSTRACT FROM AUTHOR]

Assisted vaginal birth rates are falling globally with rising cesarean delivery rates. Cesarean delivery is not without consequence, particularly when carried out in the second stage of labor. Cesarean delivery in the second stage is not entirely protective against pelvic floor morbidity and can lead to serious complications in a subsequent pregnancy. It should be acknowledged that the likelihood of morbidity for mother and baby associated with cesarean delivery increases with advancing labor and is greater than spontaneous vaginal birth, irrespective of the method of operative birth in the second stage of labor. In this article, we argue that assisted vaginal birth is a skilled and safe option that should always be considered and be available as an option for women who need assistance in the second stage of labor. Selecting the most appropriate mode of birth at full dilatation requires accurate clinical assessment, supported decision-making, and personalized care with consideration for the woman's preferences. Achieving vaginal birth with the primary instrument is more likely with forceps than with vacuum extraction (risk ratio, 0.58; 95% confidence interval, 0.39–0.88). Midcavity forceps are associated with a greater incidence of obstetric anal sphincter injury (odds ratio, 1.83; 95% confidence interval, 1.32–2.55) but no difference in neonatal Apgar score or umbilical artery pH. The risk for adverse outcomes is minimized when the procedure is conducted by a skilled accoucheur who selects the most appropriate instrument likely to achieve vaginal birth with the primary instrument. Anticipation of potential complications and dynamic decision-making are just as important as the technique for safe instrument use. Good communication with the woman and the birthing partner is vital and there are various recommendations on how to achieve this. There have been recent developments (such as OdonAssist) in device innovation, training, and strategies for implementation at a scale that can provide opportunities for both improved outcomes and reinvigoration of an essential skill that can save mothers' and babies' lives across the world. [ABSTRACT FROM AUTHOR]

Perineal trauma after vaginal birth is common, with approximately 9 of 10 women being affected. Second-degree perineal tears are twice as likely to occur in primiparous births, with a incidence of 40%. The incidence of obstetrical anal sphincter injury is approximately 3%, with a significantly higher rate in primiparous than in multiparous women (6% vs 2%). Obstetrical anal sphincter injury is a significant risk factor for the development of anal incontinence, with approximately 10% of women developing symptoms within a year following vaginal birth. Obstetrical anal sphincter injuries have significant medicolegal implications and contribute greatly to healthcare costs. For example, in 2013 and 2014, the economic burden of obstetrical anal sphincter injuries in the United Kingdom ranged between £3.7 million (with assisted vaginal birth) and £9.8 million (with spontaneous vaginal birth). In the United States, complications associated with trauma to the perineum incurred costs of approximately $83 million between 2007 and 2011. It is therefore crucial to focus on improvements in clinical care to reduce this risk and minimize the development of perineal trauma, particularly obstetrical anal sphincter injuries. Identification of risk factors allows modification of obstetrical practice with the aim of reducing the rate of perineal trauma and its attendant associated morbidity. Risk factors associated with second-degree perineal trauma include increased fetal birthweight, operative vaginal birth, prolonged second stage of labor, maternal birth position, and advanced maternal age. With obstetrical anal sphincter injury, risk factors include induction of labor, augmentation of labor, epidural, increased fetal birthweight, fetal malposition (occiput posterior), midline episiotomy, operative vaginal birth, Asian ethnicity, and primiparity. Obstetrical practice can be modified both antenatally and intrapartum. The evidence suggests that in the antenatal period, perineal massage can be commenced in the third trimester of pregnancy to increase muscle elasticity and allow stretching of the perineum during birth, thereby reducing the risk of tearing or need for episiotomy. With regard to the intrapartum period, there is a growing body of evidence from the United Kingdom, Norway, and Denmark suggesting that the implementation of quality improvement initiatives including the training of clinicians in manual perineal protection and mediolateral episiotomy can reduce the incidence of obstetrical anal sphincter injury. With episiotomy, the International Federation of Gynecology and Obstetrics recommends restrictive rather than routine use of episiotomy. This is particularly the case with unassisted vaginal births. However, there is a role for episiotomy, specifically mediolateral or lateral, with assisted vaginal births. This is specifically the case with nulliparous vacuum and forceps births, given that the use of mediolateral or lateral episiotomy has been shown to significantly reduce the incidence of obstetrical anal sphincter injury in these groups by 43% and 68%, respectively. However, the complications associated with episiotomy including perineal pain, dyspareunia, and sexual dysfunction should be acknowledged. Despite considerable research, interventions for reducing the risk of perineal trauma remain a subject of controversy. In this review article, we present the available data on the prevention of perineal trauma by describing the risk factors associated with perineal trauma and interventions that can be implemented to prevent perineal trauma, in particular obstetrical anal sphincter injury. [ABSTRACT FROM AUTHOR]

The second stage of labor extends from complete cervical dilatation to delivery. During this stage, descent and rotation of the presenting part occur as the fetus passively negotiates its passage through the birth canal. Generally, descent begins during the deceleration phase of dilatation as the cervix is drawn upward around the fetal presenting part. The most common means of assessing the normality of the second stage of labor is to measure its duration, but progress can be more meaningfully gauged by measuring the change in fetal station as a function of time. Accurate clinical identification and evaluation of differences in patterns of fetal descent are necessary to assess second stage of labor progress and to make reasoned judgments about the need for intervention. Three distinct graphic abnormalities of the second stage of labor can be identified: protracted descent, arrest of descent, and failure of descent. All abnormalities have a strong association with cephalopelvic disproportion but may also occur in the presence of maternal obesity, uterine infection, excessive sedation, and fetal malpositions. Interpretation of the progress of fetal descent must be made in the context of other clinically discernable events and observations. These include fetal size, position, attitude, and degree of cranial molding and related evaluations of pelvic architecture and capacity to accommodate the fetus, uterine contractility, and fetal well-being. Oxytocin infusion can often resolve an arrest or failure of descent or a protracted descent caused by an inhibitory factor, such as a dense neuraxial block. It should be used only if thorough assessment of fetopelvic relationships reveals a low probability of cephalopelvic disproportion. The value of forced Valsalva pushing, fundal pressure, and routine episiotomy has been questioned. They should be used selectively and where indicated. [ABSTRACT FROM AUTHOR]

Fetal head descent can be expressed as fetal station and engagement. Station is traditionally based on clinical vaginal examination of the distal part of the fetal skull and related to the level of the ischial spines. Engagement is based on a transabdominal examination of the proximal part of the fetal head above the pelvic inlet. Clinical examinations are subjective, and objective measurements of descent are warranted. Ultrasound is a feasible diagnostic tool in labor, and fetal lie, station, position, presentation, and attitude can be examined. This review presents an overview of fetal descent examined with ultrasound. Ultrasound was first introduced for examining fetal descent in 1977. The distance from the sacral tip to the fetal skull was measured with A-mode ultrasound, but more convenient transperineal methods have since been published. Of those, progression distance, angle of progression, and head-symphysis distance are examined in the sagittal plane, using the inferior part of the symphysis pubis as reference point. Head-perineum distance is measured in the frontal plane (transverse transperineal scan) as the shortest distance from perineum to the fetal skull, representing the remaining part of the birth canal for the fetus to pass. At high stations, the fetal head is directed downward, followed with a horizontal and then an upward direction when the fetus descends in the birth canal and deflexes the head. Head descent may be assessed transabdominally with ultrasound and measured as the suprapubic descent angle. Many observational studies have shown that fetal descent assessed with ultrasound can predict labor outcome before induction of labor, as an admission test, and during the first and second stage of labor. Labor progress can also be examined longitudinally. The International Society of Ultrasound in Obstetrics and Gynecology recommends using ultrasound in women with prolonged or arrested first or second stage of labor, when malpositions or malpresentations are suspected, and before an operative vaginal delivery. One single ultrasound parameter cannot tell for sure whether an instrumental delivery is going to be successful. Information about station and position is a prerequisite, but head direction, presentation, and attitude also should be considered. [ABSTRACT FROM AUTHOR]

Although the optimal length of the second stage of labor to minimize maternal and neonatal morbidities and optimize spontaneous vaginal delivery is not known, available evidence suggests that increasing length of the second stage is associated with increasing maternal and neonatal morbidity. Thus, evidence-based strategies to safely shorten the second stage, such as initiating pushing when complete dilation is reached among those with neuraxial anesthesia, is prudent. Many aspects of optimal management of the second stage of labor require future study to continue to guide clinical second-stage management. [ABSTRACT FROM AUTHOR]

The first written guide for birth plans was introduced in 1980 as a means for birthing people to document their choices in the child birthing experience. The birth plan offers an opportunity for the patient and the provider to discuss the birthing process and determine how to safely accommodate patient preferences. Patient satisfaction with birthing plans is variable and may depend on how many requests they have, how many of their plans are accomplished, route of delivery, and whether complications arise during or after delivery. Unmet expectations may lead to posttraumatic stress disorder, but following a birth plan may also be protective against it. Birthing people who use a birth plan may be less likely to use epidural anesthesia, have early amniotomy, or use oxytocin. The first stage of labor may be longer when a birth plan is used; however, there does not seem to be a decrease in the length of the second stage of labor among patients with a birth plan. Some providers believe that a disadvantage of birth plans is disappointment when birth plans are not able to be followed, and others consider that birth plans interfere with professional autonomy. [ABSTRACT FROM AUTHOR]

The past 20 years witnessed an invigoration of research on labor progression and a change of thinking regarding normal labor. New evidence is emerging, and more advanced statistical methods are applied to labor progression analyses. Given the wide variations in the onset of active labor and the pattern of labor progression, there is an emerging consensus that the definition of abnormal labor may not be related to an idealized or average labor curve. Alternative approaches to guide labor management have been proposed; for example, using an upper limit of a distribution of labor duration to define abnormally slow labor. Nonetheless, the methods of labor assessment are still primitive and subject to error; more objective measures and more advanced instruments are needed to identify the onset of active labor, monitor labor progression, and define when labor duration is associated with maternal/child risk. Cervical dilation alone may be insufficient to define active labor, and incorporating more physical and biochemical measures may improve accuracy of diagnosing active labor onset and progression. Because the association between duration of labor and perinatal outcomes is rather complex and influenced by various underlying and iatrogenic conditions, future research must carefully explore how to integrate statistical cut-points with clinical outcomes to reach a practical definition of labor abnormalities. Finally, research regarding the complex labor process may benefit from new approaches, such as machine learning technologies and artificial intelligence to improve the predictability of successful vaginal delivery with normal perinatal outcomes. [ABSTRACT FROM AUTHOR]

Epidural analgesia is an important means of pain control during labor throughout the world. Over its historic development, it has been implicated in several undesirable outcomes, including prolongation of labor and increased need for operative delivery. These effects have emerged in some retrospective and observational studies, but such methods of investigation are highly prone to bias and are particularly ill-suited for the study of labor analgesia. In high-quality studies, including Cochrane reviews and meta-analyses, epidural analgesia has been suggested to extend the first stage of labor by 30 minutes and the second stage by 15 minutes, when compared with alternative forms of analgesia. Although this may be a reproducible effect, it may be argued that it is clinically negligible. With respect to mode of delivery, similar high-quality studies have consistently shown no increased risk of cesarean delivery associated with epidural analgesia. Some forms of epidural analgesia were associated with higher risk of assisted vaginal delivery, but the use of newer modalities has been shown to abolish this effect. Specific advancements have centered on reducing total anesthetic consumption, given that local anesthetic-induced motor block is theorized to interfere with maternal expulsive efforts in the second stage of labor. These measures include the use of low-concentration local anesthetic solutions equivalent to ≤0.1% bupivacaine, shown in meta-analyses to lead to no higher risk of assisted vaginal delivery relative to nonepidural analgesia. Additional advancements in the maintenance of analgesia include programmed intermittent epidural bolus and patient-controlled epidural analgesia, the combination of which has been shown to reduce the risk of assisted vaginal delivery, also likely mediated by reduction in local anesthetic dose. These techniques have gained popularity in the past two decades, such that studies published since 2005 show no higher risk of assisted vaginal delivery with epidural than with opioid analgesia (as reported in a Cochrane review). Labor epidural analgesia has implications for maternal and fetal health perinatally. It is known to result in transient maternal hypotension (particularly with initiation), which may progress to the level of necessitating fluid or vasopressor therapy. This is not clearly associated with any adverse outcomes. There is also a consistently higher incidence of fever in parturients receiving neuraxial anesthesia, likely of noninfectious origin, which has similarly not been associated with adverse neonatal outcomes. Finally, neonates of parturients who receive epidural analgesia have been shown to have no worse Apgar scores and more favorable acid-base status than their counterparts. These observations should serve to reassure providers that modern labor analgesia, as currently understood, is not consistently associated with any significant adverse outcomes for the parturient or fetus. In this review, we describe variations of modern labor epidural analgesia, conduct an in-depth review of current literature on its use, and explore the most up-to-date evidence on its implications for the progression and outcomes of labor, including the pertinent maternal and fetal side effects. [ABSTRACT FROM AUTHOR]

Healthcare professionals working in labor wards worldwide regularly deal with the pressure of managing an emotionally charged and life-changing period for women, their families, and their friends. Furthermore, they frequently deal with long working hours, sleep deprivation, occasional scrutiny from the press, and legal dispute. The existing disagreements among leading scientific institutions on basic concepts of intrapartum care hinder the creation of a collective mental model in the labor ward, an aspect that is required for consistency in patient counseling and effective teamwork. Some of these disagreements are as follows: 1. When should laboring women be admitted to the hospital? 2. How long is the absence of labor progress acceptable before an intervention is proposed? 3. How long should women be allowed to push during the second stage of labor before an intervention is proposed? The international scientific community owes it to the vast number of healthcare professionals working in labor wards worldwide to agree on and provide clear definitions of these basic intrapartum concepts, thus making their work a little easier. International institutions, such as the International Federation of Gynecology and Obstetrics and the World Health Organization, have the highest authority to produce guidelines for the whole world, but the participation of leading national organizations, whose influence reaches well beyond the borders of their countries, is important for the wide dissemination of concepts. [ABSTRACT FROM AUTHOR]

Objective: The primary objective of this systematic review was to assess the association between spontaneous vaginal delivery and manual rotation during labor for occiput posterior or transverse positions. Our secondary objective was to assess maternal and neonatal outcomes.Data Sources: An electronic search of PubMed, EMBASE, ClinicalTrials.gov, and the Cochrane Register of Controlled Trials covered the period from January 2000 to September 2021, without language restrictions.Study Eligibility Criteria: The eligibility criteria included all randomized trials with singleton pregnancies at ≥37 weeks of gestation comparing the manual rotation groups with the control groups. The primary outcome was the rate of spontaneous vaginal delivery. Additional secondary outcomes were rate of occiput posterior position at delivery, operative vaginal delivery, cesarean delivery, postpartum hemorrhage, obstetrical anal sphincter injury, prolonged second stage of labor, shoulder dystocia, neonatal acidosis, and phototherapy. Subgroup analyses were performed according to types of position (occiput posterior or occiput transverse), techniques used (whole-hand or digital rotation), and parity (nulliparous or parous).Methods: The quality of each study was evaluated with the revised Cochrane risk-of-bias tool for randomized trials, known as RoB 2. The meta-analysis used random-effects models depending on their heterogeneity, and risks ratios were calculated for dichotomous outcomes.Results: Here, 7 of 384 studies met the inclusion criteria and were selected. They included 1402 women: 704 in the manual rotation groups and 698 in the control groups. Manual rotation was associated with a higher rate of spontaneous vaginal delivery: 64.9% vs 59.5% (risk ratio, 1.09; 95% confidence interval, 1.03-1.16; P=.005; 95% prediction interval, 0.90-1.32). This association was no longer significant after stratification by parity or technique used. Manual rotation was associated with spontaneous vaginal delivery only for the occiput posterior position (risk ratio, 1.08; 95% confidence interval, 1.01-1.15). Furthermore, it was associated with a reduction in occiput posterior or transverse positions at delivery (risk ratio, 0.64; 95% confidence interval, 0.48-0.87) and episiotomies (risk ratio, 0.84; 95% confidence interval, 0.71-0.98). The groups did not differ significantly for cesarean deliveries, operative vaginal deliveries, or neonatal outcomes.Conclusion: Manual rotation increased the rate of spontaneous vaginal delivery. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to assess the efficacy of sonographic assessment of fetal occiput position before operative vaginal delivery to decrease the number of failed operative vaginal deliveries.Data Sources: The search was conducted in MEDLINE, Embase, Web of Science, Scopus, ClinicalTrial.gov, Ovid, and Cochrane Library as electronic databases from the inception of each database to April 2021. No restrictions for language or geographic location were applied.Study Eligibility Criteria: Selection criteria included randomized controlled trails of pregnant women randomized to either sonographic or clinical digital diagnosis of fetal occiput position during the second stage of labor before operative vaginal delivery.Methods: The primary outcome was failed operative vaginal delivery, defined as a failed fetal operative vaginal delivery (vacuum or forceps) extraction requiring a cesarean delivery or forceps after failed vacuum. The summary measures were reported as relative risks or as mean differences with 95% confidence intervals using the random effects model of DerSimonian and Laird. An I2 (Higgins I2) >0% was used to identify heterogeneity.Results: A total of 4 randomized controlled trials including 1007 women with singleton, term, cephalic fetuses randomized to either the sonographic (n=484) or clinical digital (n=523) diagnosis of occiput position during the second stage of labor before operative vaginal delivery were included. Before operative vaginal delivery, fetal occiput position was diagnosed as anterior in 63.5% of the sonographic diagnosis group vs 69.5% in the clinical digital diagnosis group (P=.04). There was no significant difference in the rate of failed operative vaginal deliveries between the sonographic and clinical diagnosis of occiput position groups (9.9% vs 8.2%; relative risk, 1.14; 95% confidence interval, 0.77-1.68). Women randomized to sonographic diagnosis of occiput position had a significantly lower rate of occiput position discordance between the evaluation before operative vaginal delivery and the at birth evaluation when compared with those randomized to the clinical diagnosis group (2.3% vs 17.7%; relative risk, 0.16; 95% confidence interval, 0.04-0.74; P=.02). There were no significant differences in any of the other secondary obstetrical and perinatal outcomes assessed.Conclusion: Sonographic knowledge of occiput position before operative vaginal delivery does not seem to have an effect on the incidence of failed operative vaginal deliveries despite better sonographic accuracy in the occiput position diagnosis when compared with clinical assessment. Future studies should evaluate how a more accurate sonographic diagnosis of occiput position or other parameters can lead to a safer and more effective operative vaginal delivery technique. [ABSTRACT FROM AUTHOR]

The effect on obstetrical outcomes of closed- or open-glottis pushing is uncertain among both nulliparous and parous women. This study aimed to assess the association between open- or closed-glottis pushing and mode of delivery after an attempted singleton vaginal birth at or near term. This was an ancillary planned cohort study of the TRAAP (TRAnexamic Acid for Preventing postpartum hemorrhage after vaginal delivery) randomized controlled trial, conducted in 15 French maternity units from 2015 to 2016 that enrolled women with an attempted singleton vaginal delivery after 35 weeks' gestation. After randomization, characteristics of labor and delivery were prospectively collected, with special attention to active second-stage pushing and a specific planned questionnaire completed immediately after birth by the attending care provider. The exposure was the mode of pushing, classified into 2 groups: closed- or open-glottis. The main endpoint was operative vaginal delivery. Secondary endpoints were items of maternal morbidity, including severe perineal laceration, episiotomy, postpartum hemorrhage, duration of the second stage of labor, and a composite severe neonatal morbidity outcome. We also assessed immediate maternal satisfaction, experience of delivery, and psychological status 2 months after delivery. The associations between mode of pushing and outcome were analyzed by multivariate logistic regression to control for confounding bias, with multilevel mixed-effects analysis, and a random intercept for center. Among 3041 women included in our main analysis, 2463 (81.0%) used closed-glottis pushing and 578 (19.0%) open-glottis pushing; their respective operative vaginal delivery rates were 19.1% (n=471; 95% confidence interval, 17.6–20.7) and 12.5% (n=72; 95% confidence interval, 9.9–15.4; P <.001). In an analysis stratified according to parity and after controlling for available confounders, the rate of operative vaginal delivery did not differ between the groups among nulliparous women: 28.7% (n=399) for the closed-glottis and 27.5% (n=64) for the open-glottis group (adjusted odds ratio, 0.93; 95% confidence interval, 0.65–1.33; P =.7). The operative vaginal delivery rate was significantly lower for women using open- compared with closed-glottis pushing in the parous population: 2.3% (n=8) for the open- and 6.7% (n=72) for the closed-glottis groups (adjusted odds ratio, 0.43; 95% confidence interval, 0.19–0.90; P =.03). Other maternal and neonatal outcomes did not differ between the 2 modes of pushing among either the nulliparous or parous groups. Among nulliparous women with singleton pregnancies at term, the risk of operative vaginal birth did not differ according to mode of pushing. These results will inform shared decision-making about the mode of pushing during the second stage of labor. [ABSTRACT FROM AUTHOR]

Decreasing rates of assisted vaginal birth have been paralleled with increasing rates of cesarean deliveries over the last 40 years. The OdonAssist is a novel device for assisted vaginal birth. Iterative changes to clinical parameters, device design, and technique have been made to improve device efficacy and usability. This study aimed to determine if the feasibility, safety, and efficacy of the OdonAssist device were sufficient to justify conducting a future randomized controlled trial. An open-label nonrandomized study of 104 participants having a clinically indicated assisted vaginal birth using the OdonAssist was undertaken at Southmead Hospital, Bristol, United Kingdom. Data were also collected from participants who consented to participate in the study but for whom trained OdonAssist operators were not available, providing a nested cohort. The primary clinical outcome was the proportion of births successfully expedited with the OdonAssist. Secondary outcomes included clinical, patient-reported, operator-reported, device and health care utilization. Neonatal outcome data were reviewed at day 28, and maternal outcomes were investigated up to day 90. Given that the number of successful OdonAssist births was ≥61 out of 104, the hypothesis of a poor rate of 50% was rejected in favor of a good rate of ≥65%. Between August 2019 and June 2021, 941 (64%) of the 1471 approached, eligible participants consented to participate. Of these, 104 received the OdonAssist intervention. Birth was assisted in all cephalic vertex fetal positions, at all stations ≥1 cm below the ischial spines (with or without regional analgesia). The OdonAssist was effective in 69 of the 104 (66%) cases, consistent with the hypothesis of a good efficacy rate. There were no serious device-related maternal or neonatal adverse reactions, and there were no serious adverse device effects. Only 4% of neonatal soft tissue bruising in the successful OdonAssist group was considered device-related, as opposed to 20% and 23% in the unsuccessful OdonAssist group and the nested cohort, respectively. Participants reported high birth perception scores. All practitioners found the device use to be straightforward. Recruitment to an interventional study of a new device for assisted vaginal birth is feasible; 64% of eligible participants were willing to participate. The success rate of the OdonAssist was comparable to that of the Kiwi OmniCup when introduced in the same unit in 2002, meeting the threshold for a randomized controlled trial to compare the OdonAssist with current standard practice. There were no disadvantages of study participation in terms of maternal and neonatal outcomes. There were potential advantages of using the OdonAssist, particularly reduced neonatal soft tissue injury. The same application technique is used for all fetal positions, with all operators deeming the device straightforward to use. This study provides important data to inform future study design. [ABSTRACT FROM AUTHOR]

This study aimed to quantify the association between mode of operative delivery in the second stage of labor (cesarean delivery vs operative vaginal delivery) and spontaneous preterm birth in a subsequent pregnancy. MEDLINE, Embase, EmCare, CINAHL, the Cochrane Library, Web of Science: Core Collection, and Scopus were searched from database inception to April 1, 2023. All retrospective cohort studies with participants who had a second-stage cesarean delivery (defined as intrapartum cesarean delivery at full cervical dilation) or operative vaginal delivery (including forceps- and/or vacuum-assisted delivery) and that reported the rate of preterm birth (either spontaneous or not specified) in subsequent pregnancy were included. Both a descriptive analysis and a meta-analysis were performed. A meta-analysis was performed for dichotomous data using the Mantel-Haenszel random-effects model and used the odds ratio as an effect measure with 95% confidence intervals. The risk of bias was assessed using Cochrane's 2022 Risk Of Bias In Non-randomized Studies of Exposure tool. After screening 2671 articles from 7 databases, a total of 18 retrospective cohort studies encompassing 605,138 patients were included. The pooled rates of spontaneous preterm birth in a subsequent pregnancy were 6.9% (12 studies) after second-stage cesarean delivery and 2.6% (8 studies) after operative vaginal delivery. A total of 7 studies encompassing 75,460 patients compared the primary outcome of spontaneous preterm birth after second-stage cesarean delivery vs operative vaginal delivery in an index pregnancy with an odds ratio of 2.01 (95% confidence interval, 1.57–2.58) in favor of operative vaginal delivery. However, most studies did not include important confounding factors, did not address exposure misclassification because of failed operative vaginal delivery, and considered operative vaginal delivery as a homogeneous category with no distinction between forceps- and vacuum-assisted deliveries. Although a synthesis of the existing literature suggests that the risk of spontaneous preterm birth is higher in those with a previous second-stage cesarean delivery than in those with operative vaginal delivery, the risk of bias in these studies is very high. Findings should be interpreted with caution. [ABSTRACT FROM AUTHOR]

Having a cesarean delivery at full dilatation has been associated with increased subsequent risk of spontaneous preterm birth. The Aberdeen Maternity and Neonatal Databank provides a rare opportunity to study subsequent pregnancy outcomes after a previous cesarean delivery at full dilatation over 40 years, with an ability to include a detailed evaluation of potential confounding factors. This study aimed to investigate if having an initial cesarean delivery at full dilatation is associated with spontaneous preterm birth or other adverse pregnancy outcomes in the subsequent pregnancy. A retrospective cohort study was conducted including women with a first and second pregnancy recorded within the Aberdeen Maternity and Neonatal Databank between 1976 and 2017, where previous cesarean delivery at full dilatation at term in the first birth was the exposure. The primary outcome was spontaneous preterm birth (defined as spontaneous birth <37 weeks). Multivariate logistic regression was used to investigate any association between cesarean delivery at full dilatation and the odds of spontaneous preterm birth. Cesarean delivery at full dilatation in previous pregnancy was compared with: (1) any other mode of birth, and (2) individual modes of birth, including planned cesarean delivery, cesarean delivery in first stage of labor (<10-cm dilatation), and vaginal birth (including spontaneous vaginal birth, nonrotational forceps, Kielland forceps, vacuum-assisted birth, breech vaginal birth). Other outcomes such as antepartum hemorrhage and mode of second birth were also compared. Of the 30,253 women included, 900 had a previous cesarean delivery at full dilatation in the first pregnancy. Women with previous cesarean delivery at full dilatation had a 3-fold increased risk of spontaneous preterm birth in a second pregnancy (unadjusted odds ratio, 2.63; 95% confidence interval, 1.82–3.81; adjusted odds ratio, 3.31; 95% confidence interval, 2.17–5.05) compared with those with all other modes of first birth, adjusted for maternal age, diabetes mellitus, body mass index, smoking, preeclampsia, antepartum hemorrhage, socioeconomic deprivation (Scottish Index of Multiple Deprivation 2016), year of birth, and interpregnancy interval (in second pregnancy). When compared with women with vaginal births only, women with cesarean delivery at full dilatation had 5-fold increased odds of spontaneous preterm birth (adjusted odds ratio, 5.37; 95% confidence interval, 3.40–8.48). Compared with first spontaneous vaginal birth, first instrumental births (nonrotational forceps, Kielland forceps, and vacuum births) were not associated with increased risk of spontaneous preterm birth in the second birth. After an initial cesarean delivery at full dilatation, 3.7% of women had a repeated cesarean delivery at full dilatation and 48% had a planned cesarean delivery in the second birth. This study is a substantial addition to the body of evidence on the risk of subsequent spontaneous preterm birth after cesarean delivery at full dilatation, and demonstrates a strong association between cesarean delivery at full dilatation in the first birth and spontaneous preterm birth in subsequent pregnancy, although the absolute risk remains small. This is a large retrospective cohort and includes a comprehensive assessment of potential confounding factors, including preeclampsia, antepartum hemorrhage, and lengths of first and second stage of labor. Future research should focus on understanding possible causality and developing primary and secondary preventative measures. [ABSTRACT FROM AUTHOR]

Objective: The aim of this systematic review and meta-analysis of randomized controlled trials was to evaluate the effect of delayed versus immediate pushing in the second stage of labor on mode of delivery and other outcomes in women with neuraxial analgesia.Data Sources: The research was conducted using MEDLINE, EMBASE, Web of Sciences, Scopus, ClinicalTrial.gov, OVID, and the Cochrane Library as electronic databases, from the inception of each database to August 2019. No restrictions for language or geographic location were applied.Study Eligibility Criteria: Selection criteria included only randomized controlled trials in pregnant women randomized to either delayed or immediate pushing during the second stage of labor.Study Appraisal and Synthesis Methods: The primary outcome was mode of delivery. The summary measures were reported as relative risk or as mean difference with 95% confidence intervals using the random effects model of DerSimonian and Laird. An I2 (Higgins I2) value of greater than 0% was used to identify heterogeneity.Results: Twelve randomized controlled trials, including 5445 women with neuraxial analgesia randomized to delayed versus immediate pushing during the second stage of labor, were included in the meta-analysis. Of the 5445 women included in the meta-analysis, 2754 were randomized to the delayed pushing group and 2691 to the immediate pushing group. No significant difference between delayed and immediate pushing was found for spontaneous vaginal delivery (80.9% versus 78.3%; relative risk, 1.05; 95% confidence interval, 1.00-1.10; 12 randomized controlled trials, 5540 women), operative vaginal delivery (12.8% versus 14.6%; relative risk, 0.89; 95% confidence interval, 0.75-1.08; 11 randomized controlled trials, 5395 women), and cesarean delivery (6.9% versus 7.9%; relative risk, 0.89; 95% confidence interval, 0.73-1.07; 11 randomized controlled trials; 5395 women). Women randomized to the delayed pushing group had a significantly shorter length of active pushing (mean difference, -27.54 minutes; 95% confidence interval, -43.04 to -12.04; 7 randomized controlled trials, 4737 women) at the expense of a significantly longer overall duration of the second stage of labor (mean difference, 46.17 minutes; 95% confidence interval, 32.63-59.71; 8 studies; 4890 women). The incidence of chorioamnionitis (9.1% versus 6.6%; relative risk, 1.37, 95% confidence interval, 1.04-1.81; 1 randomized controlled trial, 2404 women) and low umbilical cord pH (2.7% versus 1.3%; relative risk, 2.00; 95% confidence interval, 1.30-3.07; 5 randomized controlled trials, 4549 women) were significantly higher in the delayed pushing group.Conclusion: In women with spontaneous or induced labor at term with neuraxial analgesia, delayed pushing in the second stage does not affect the mode of delivery, although it reduces the time of active pushing at the expense of a longer second stage. This prolongation of labor was associated with a higher incidence of chorioamnionitis and low umbilical cord pH. Based on these findings, delayed pushing cannot be routinely advocated for the management of the second stage. [ABSTRACT FROM AUTHOR]

Incontinence occurs frequently in the postpartum period. Several theoretical pathophysiological models may underlie the hypothesis that different types of management of the active phase of the second stage of labor have different effects on pelvic floor muscles and thus perhaps affect urinary and anal continence. This study aimed to evaluate the impact of "moderate pushing" on the occurrence of urinary or anal incontinence compared with "intensive pushing," and to determine the factors associated with incontinence at 6 months postpartum. This was a planned analysis of secondary objectives of the PASST (Phase Active du Second STade) trial, a multicenter randomized controlled trial. PASST included nulliparous women with singleton term pregnancies and epidural analgesia, who were randomly assigned at 8 cm of dilatation to either the intervention group that used "moderate" pushing (pushing only twice during each contraction, resting regularly for 1 contraction in 5 without pushing, and no time limit on pushing) or the control group following the usual management of "intensive" pushing (pushing 3 times during each contraction, with no contractions without pushing, with an obstetrician called to discuss operative delivery after 30 minutes of pushing). Data about continence were collected with validated self-assessment questionnaires at 6 months postpartum. Urinary incontinence was defined by an ICIQ-UI SF (International Consultation on Incontinence Questionnaire–Urinary Incontinence Short Form) score ≥1 and anal incontinence by a Wexner score ≥2. A separate analysis was also performed among the more severely affected women (ICIQ-UI SF ≥6 and Wexner ≥5). Factors associated with incontinence were assessed with univariate and multivariable analyses. Among 1618 women initially randomized, 890 (55%) returned the complete questionnaire at 6 months. The rate of urinary incontinence was 36.6% in the "moderate" pushing group vs 38.5% in the "intensive" pushing group (relative risk, 0.95; 95% confidence interval, 0.80–1.13), whereas the rate of anal incontinence was 32.2% vs 34.6% (relative risk, 0.93; 95% confidence interval, 0.77–1.12). None of the obstetrical factors studied related to the second stage of labor influenced the occurrence of urinary or anal incontinence, except operative vaginal delivery, which increased the risk of anal incontinence (adjusted odds ratio, 1.50; 95% confidence interval, 1.04–2.15). The results of the PASST trial indicate that neither moderate nor intensive pushing efforts affect the risk of urinary or anal incontinence at 6 months postpartum among women who gave birth under epidural analgesia. [ABSTRACT FROM AUTHOR]

A prolonged second stage of labor increases the risk of severe perineal laceration, postpartum hemorrhage, operative delivery, and poor Apgar score. The second stage is longer in nulliparas. Maternal pushing during the second stage of labor is an important contributor to the involuntary expulsive force developed by uterine contraction to deliver the fetus. Preliminary data indicate that visual biofeedback during the active second stage hastens birth. This study aimed to evaluate if visual feedback focusing on the perineum reduced the length of the active second stage of labor in comparison with the control. A randomized controlled trial was conducted in the University Malaya Medical Centre from December 2021 to August 2022. Nulliparous women about to commence the active second stage, at term, with singleton gestation, reassuring fetal status, and no contraindication for vaginal delivery were randomized to live viewing of the maternal introitus (intervention) or maternal face (sham/placebo control) as visual biofeedback during their pushing. A video camera Bluetooth-linked to a tablet computer display screen was used; in the intervention arm, the camera was focused on the introitus, and in the control arm, on the maternal face. Participants were instructed to watch the display screen during their pushing. The primary outcomes were the intervention-to-delivery interval and maternal satisfaction with the pushing experience assessed using a 0-to-10 visual numerical rating scale. Secondary outcomes included mode of delivery, perineal injury, delivery blood loss, birthweight, umbilical cord arterial blood pH and base excess at birth, Apgar score at 1 and 5 minutes, and neonatal intensive care unit admission. Data were analyzed with the t test, Mann-Whitney U test, chi-square test, and Fisher exact test, as appropriate. A total of 230 women were randomized (115 to intervention and 115 to control arm). The active second stage duration (intervention-to-delivery interval) was a median (interquartile range) of 16 (11–23) and 17 (12–31) minutes (P =.289), and maternal satisfaction with the pushing experience was 9 (8–10) and 7 (6–7) (P <.001) for the intervention and control arm, respectively. Women randomized to the intervention arm were more likely to agree to recommend their management to a friend (88/115 [76.5%] vs 39/115 [33.9%]; relative risk, 2.26 [95% confidence interval, 1.72–2.97]; P <.001) and more likely to have less severe perineal injury (P =.018). Real-time viewing of the maternal introitus as visual biofeedback during pushing resulted in higher maternal satisfaction compared with the sham control of viewing the maternal face; however, the time to delivery was not significantly shortened. [ABSTRACT FROM AUTHOR]

The second stage of labor requires active patient engagement. Previous studies suggest that coaching can influence the second stage of labor duration. However, a standardized education tool has not been established, and patients face many barriers to accessing childbirth education before delivery. This study aimed to investigate the effect of an intrapartum video pushing education tool on the second stage of labor duration. This was a randomized controlled trial of nulliparous patients with singleton pregnancies ≥37 weeks of gestation admitted for induction of labor or spontaneous labor with neuraxial anesthesia. Patients were consented on admission and block randomized in active labor to 1 of 2 arms in a 1:1 ratio. The study arm viewed a 4-minute video before the second stage of labor on what to anticipate in the second stage of labor and pushing techniques. The control arm received the standard of care: bedside coaching at 10 cm dilation from a nurse or physician. The primary outcome was second stage of labor duration. The secondary outcomes were birth satisfaction (using the Modified Mackey Childbirth Satisfaction Rating Scale), mode of delivery, postpartum hemorrhage, clinical chorioamnionitis, neonatal intensive care unit admission, and umbilical artery gases. Of note, 156 patients were needed to detect a 20% decrease in the second stage of labor duration with 80% power, 2-sided alpha level of.05, and 10% loss after randomization. Funding was provided by the Lucy Anarcha Betsy award from the division of clinical research at Washington University. Of 161 patients, 81 were randomized to standard of care, and 80 were randomized to intrapartum video education. Among these patients, 149 progressed to the second stage of labor and were included in the intention-to-treat analysis: 69 in the video group and 78 in the control group. Maternal demographics and labor characteristics were similar between groups. The second stage of labor duration was statistically similar between the video arm (61 minutes [interquartile range, 20–140]) and the control arm (49 minutes [interquartile range, 27–131]) (P =.77). There was no difference in mode of delivery, postpartum hemorrhage, clinical chorioamnionitis, neonatal intensive care unit admission, or umbilical artery gases between groups. Although the overall birth satisfaction score on the Modified Mackey Childbirth Satisfaction Rating Scale was similar between groups, patients in the video group rated their "level of comfort during birth" and "attitude of the doctors in birth" significantly higher or more positively than patients in the control group (P <.05 for both). Intrapartum video education was not associated with a shorter second stage of labor duration. However, patients who received video education reported a higher level of comfort and a more favorable perception of their physician, suggesting that video education may be a helpful tool to improve the birth experience. [ABSTRACT FROM AUTHOR]

Little is known about the latent phase of labor, including whether its duration influences subsequent labor processes or birth outcomes. This study aimed to describe the duration of the latent phase of labor from self-report of the onset of painful contractions to a cervical dilation of 5 cm in a large, Swedish population and evaluate the association between the duration of the latent phase of labor and perinatal processes and outcomes that occurred during the active phase of labor, second stage of labor, birth and immediately after delivery, stratified by parity. This was a population-based cohort study of 67,267 pregnancies with deliveries between 2008 and 2020 in the Stockholm-Gotland Regions, Sweden. Nulliparous and parous women without a history of cesarean delivery in spontaneous labor with a term (≥37 weeks of gestation), singleton, live, and vertex fetus without major malformations were included. Imputation was used if the notation of the end of the latent phase of labor (ie, cervical dilation of 5 cm) was missing in the partograph. Multivariable logistic regression was used to estimate the association with adjusted odds ratios and 95% confidence intervals, controlling for potential covariates. Including the time from painful contraction onset to a cervical dilation of 5 cm, the median durations of the latent phase of labor were 16.0 (interquartile range, 10.0–26.6) hours for nulliparous women and 9.4 (interquartile range, 5.9–15.3) hours for multiparous women. The durations of the latent phase of labor beyond the median were associated with increased odds of labor dystocia diagnosis during the first stage active phase or second stage of labor and interventions commonly associated with dystocia (amniotomy, oxytocin augmentation, epidural, and cesarean delivery). The duration of the latent phase of labor of ≥90th percentile vs less than the median in nulliparous women demonstrated an increased risk of adverse neonatal outcomes (Apgar score of <7 at 5 minutes and neonatal intensive care unit admission), chorioamnionitis, and fetal occiput posterior. In multiparous women, longer duration of the latent phase of labor was associated with an increased risk of neonatal intensive care unit admission and chorioamnionitis but was not associated with an Apgar score of <7 at 5 minutes. The duration of the latent phase of labor was not associated with additional markers of maternal risk. The duration of the latent phase of labor in nulliparous women was longer than that of multiparous women at each point of distribution. A longer duration of the latent phase of labor was associated with more frequent dystocia diagnoses and related interventions during the first stage active phase or second stage of labor, including cesarean delivery, nulliparous fetal occiput posterior position, chorioamnionitis, and markers of neonatal morbidity. More research is needed to identify potential mediating paths between the duration of the latent phase of labor and neonatal morbidity. [ABSTRACT FROM AUTHOR]

Background: There is no consensus on an optimal strategy for managing the active phase of the second stage of labor. Intensive pushing could not only reduce pushing duration, but also increase abnormal fetal heart rate because of cord compression and reduced placental perfusion and oxygenation resulting from the combination of uterine contractions and maternal expulsive forces. Therefore, it may increase the risk of neonatal acidosis and the need for operative vaginal delivery.Objective: This study aimed to assess the effect of the management encouraging "moderate" pushing vs "intensive" pushing on neonatal morbidity.Study Design: This study was a multicenter randomized controlled trial, including nulliparas in the second stage of labor with an epidural and a singleton cephalic fetus at term and with a normal fetal heart rate. Of note, 2 groups were defined: (1) the moderate pushing group, in which women had no time limit on pushing, pushed only twice during each contraction, and observed regular periods without pushing, and (2) the intensive pushing group, in which women pushed 3 times during each contraction and the midwife called an obstetrician after 30 minutes of pushing to discuss operative delivery (standard care). The primary outcome was a composite neonatal morbidity criterion, including umbilical arterial pH of <7.15, base excess of >10 mmol/L, lactate levels of >6 mmol/L, 5-minute Apgar score of <7, and severe neonatal trauma. The secondary outcomes were mode of delivery, episiotomy, obstetrical anal sphincter injuries, postpartum hemorrhage, and maternal satisfaction.Results: The study included 1710 nulliparous women. The neonatal morbidity rate was 18.9% in the moderate pushing group and 20.6% in the intensive pushing group (P=.38). Pushing duration was longer in the moderate group than in the intensive group (38.8±26.4 vs 28.6±17.0 minutes; P<.001), and its rate of operative delivery was 21.1% in the moderate group compared with 24.8% in the intensive group (P=.08). The episiotomy rate was significantly lower in the moderate pushing group than in the intensive pushing group (13.5% vs 17.8%; P=.02). We found no significant difference for obstetrical anal sphincter injuries, postpartum hemorrhage, or maternal satisfaction.Conclusion: Moderate pushing has no effect on neonatal morbidity, but it may nonetheless have benefits, as it was associated with a lower episiotomy rate. [ABSTRACT FROM AUTHOR]

Background: Uncertain fetal head engagement represents 4% of obstetrical situations associated with an increased risk of postpartum hemorrhage, notably in cases of cesarean delivery and increased neonatal impairment owing to failed vaginal instrumental delivery. In this obstetrical condition, cesarean delivery is recommended, but vaginal delivery is possible in two-thirds of the cases. During the second stage of labor, the descent of the fetal head can be assessed by sonography, particularly by measuring the angle of progression.Objective: To evaluate, after a prolonged second stage of labor, the impact of measuring the angle of progression in addition to a digital examination on cesarean delivery rates when fetal head engagement remains uncertain.Study Design: This open multicenter randomized pragmatic trial included women at term with a singleton cephalic fetus in a clinical occiput anterior position after a prolonged 2-hour second stage of labor with uncertain fetal head engagement. After inclusion in the study, an independent investigator performed ultrasound systematically to confirm the occiput anterior position and measured the angle of progression at the climax of Valsalva pushing. This operator did not participate in labor management. In the study group but not in the control group, the angle of progression was communicated to the obstetrician in charge of labor management. Obstetricians were encouraged to attempt vaginal birth if the angle of progression was >120°. The primary outcome was the cesarean delivery rate. Secondary outcomes were operative delivery rate (cesarean delivery and operative vaginal delivery), maternal complications (third and fourth-degree perineal tears, failed vaginal instrumental delivery, postpartum hemorrhage, hysterectomy), and neonatal outcomes (Apgar score <5 at 10 minutes, umbilical arterial pH <7.10, neonatal wounds, neonatal intensive care unit admission).Results: A total of 45 women were included in the study. Occiput anterior position was confirmed in 33 women: 16 in the study group and 17 in the control group. Women's characteristics at baseline were similar between the groups. The median (range) angles of progression were similar: 138.4° (15) and 140.3° (16.9) in the study and control group, respectively. Cesarean delivery rates were 12.5% in the study group and 41.1% in the control group (P=.06). Secondary outcomes were similar between the 2 groups. No failed vaginal instrumental delivery was reported.Conclusion: Measurement of the angle of progression in addition to digital examination when fetal head engagement remained uncertain showed promising results in decreasing cesarean delivery rates. A larger multicenter randomized controlled trial is needed to confirm these results. [ABSTRACT FROM AUTHOR]

Background: During the second stage of labor, the maternal pelvic floor muscles undergo repetitive stretch loading as uterine contractions and strenuous maternal pushes combined to expel the fetus, and it is not uncommon that these muscles sustain a partial or complete rupture. It has recently been demonstrated that soft tissues, including the anterior cruciate ligament and connective tissue in sheep pelvic floor muscle, can accumulate damage under repetitive physiological (submaximal) loads. It is well known to material scientists that this damage accumulation can not only decrease tissue resistance to stretch but also result in a partial or complete structural failure. Thus, we wondered whether certain maternal pushing patterns (in terms of frequency and duration of each push) could increase the risk of excessive damage accumulation in the pelvic floor tissue, thereby inadvertently contributing to the development of pelvic floor muscle injury.Objective: This study aimed to determine which labor management practices (spontaneous vs directed pushing) are less prone to accumulate damage in the pelvic floor muscles during the second stage of labor and find the optimum approach in terms of minimizing the risk of pelvic floor muscle injury.Study Design: We developed a biomechanical model for the expulsive phase of the second stage of labor that includes the ability to measure the damage accumulation because of repetitive physiological submaximal loads. We performed 4 simulations of the second stage of labor, reflecting a directed pushing technique and 3 alternatives for spontaneous pushing.Results: The finite element model predicted that the origin of the pubovisceral muscle accumulates the most damage and so it is the most likely place for a tear to develop. This result was independent of the pushing pattern. Performing 3 maternal pushes per contraction, with each push lasting 5 seconds, caused less damage and seemed the best approach. The directed pushing technique (3 pushes per contraction, with each push lasting 10 seconds) did not reduce the duration of the second stage of labor and caused higher damage accumulation.Conclusion: The frequency and duration of the maternal pushes influenced the damage accumulation in the passive tissues of the pelvic floor muscles, indicating that it can influence the prevalence of pelvic floor muscle injuries. Our results suggested that the maternal pushes should not last longer than 5 seconds and that the duration of active pushing is a better measurement than the total duration of the second stage of labor. Hopefully, this research will help to shed new light on the best practices needed to improve the experience of labor for women. [ABSTRACT FROM AUTHOR]

Background: Evidence of detachment of the levator ani muscle system is seen more frequently in patients with pelvic floor disorders. It has been suggested that passive descent of the fetus before pushing could be used to decrease operative vaginal delivery and levator ani muscle injury.Objective: This planned analysis aimed to determine whether immediate or delayed pushing was associated with an increased proportion of injury to the levator ani muscle system after the first delivery among nulliparous women.Study Design: The Optimizing Management of the Second Stage study was a multicenter randomized trial. Nulliparous women with term pregnancies and neuraxial analgesia were randomly assigned at complete cervical dilation to either immediate pushing or delayed pushing for 1 hour. A subset of participants consented to longitudinal objective pelvic floor assessments: (1) during postpartum stay (initial), (2) at 6 weeks (postpartum 1), and (3) at 6 months (postpartum 2) with transperineal 3-dimensional ultrasound. Following the completion of all visits by all subjects, saved 3-dimensional ultrasound volumes were assessed in a masked fashion. The outcome was "occult" levator ani muscle injury on the right or left, defined as a widening of the attachment of the levator ani to its origin utilizing the levator-urethra gap measurement. Measurements and proportions were compared between the 2 groups by study visit using the χ2 test or Fisher exact test for categorical variables and the t test or Mann-Whitney U test for continuous variables as appropriate.Results: Here, 941 of 2414 randomized subjects (39.0%) participated in the pelvic floor assessments: 452 in the immediate pushing group and 489 in the delayed pushing group. We obtained sonograms on 67%, 83%, and 77% of the pelvic floor assessment participants at the initial, postpartum 1, and postpartum-2 visits, respectively. Demographic and labor characteristics were comparable between the 2 groups; 94% of participants were non-Hispanic, and 50% of participants were Black. Levator ani muscle injury was noted in 77 participants (13.6%) at the initial visit, 99 (13.1%) at PP1, and 72 (10.6%) at PP2. There was no difference in injury between women in the immediate pushing group and women in the delayed pushing group. These findings did not change when the threshold (sensitivity) of levator ani muscle injury was adjusted to a less conservative measure.Conclusion: Among nulliparous women at term with neuraxial analgesia, the rates of occult levator ani muscle injury were not different between women undergoing immediate pushing and women undergoing delayed pushing in the second stage of labor. Further research efforts are needed to understand the development and potential prevention of subsequent pelvic floor disorders. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to investigate the diagnostic performance of transperineal ultrasound-measured angles of progression at the onset of the second stage of labor for the prediction of spontaneous vaginal delivery in singleton term pregnancies with cephalic presentation.Data Sources: We performed a predefined systematic search in PubMed, Embase, Scopus, Web of Science, and Google Scholar from inception to February 5, 2021.Study Eligibility Criteria: Prospective cohort studies that evaluated the diagnostic performance of transperineal ultrasound-measured angles of progression (index test) at the onset of the second stage of labor (ie, when complete cervical dilation is diagnosed) for the prediction of spontaneous vaginal delivery (reference standard) were eligible for inclusion. Eligible studies were limited to those published as full-text articles in the English language and those that included only parturients with a singleton healthy fetus at term with cephalic presentation.Study Appraisal and Synthesis Methods: Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Summary receiver operating characteristic curves, pooled sensitivities and specificities, area under the curve, and summary likelihood ratios were calculated using the Stata software. Subgroup analyses were done based on angle of progression ranges of 108° to 119°, 120° to 140°, and 141° to 153°.Results: A total of 8 studies reporting on 887 pregnancies were included. Summary estimates of the sensitivity and specificity of transperineal ultrasound-measured angle of progression at the onset of the second stage of labor for predicting spontaneous vaginal delivery were 94% (95% confidence interval, 88%-97%) and 47% (95% confidence interval, 18%-78%), respectively, for an angle of progression of 108° to 119°, 81% (95% confidence interval, 70%-89%) and 73% (95% confidence interval, 57%-85%), respectively, for an angle of progression of 120° to 140°, and 66% (95% confidence interval, 56%-74%) and 82% (95% confidence interval, 66%-92%), respectively, for an angle of progression of 141° to 153°. Likelihood ratio syntheses gave overall positive likelihood ratios of 1.8 (95% confidence interval, 1-3.3), 3 (95% confidence interval, 2-4.7), and 3.7 (95% confidence interval, 1.7-8.1) and negative likelihood ratios of 0.13 (95% confidence interval, 0.07-0.22), 0.26 (95% confidence interval, 0.18-0.38), and 0.42 (95% confidence interval, 0.29-0.60) for angle of progression ranges of 108° to 119°, 120° to 140°, and 141° to 153°, respectively.Conclusion: Angle of progression measured by transperineal ultrasound at the onset of the second stage of labor may predict spontaneous vaginal delivery in singleton, term, cephalic presenting pregnancies and has the potential to be used along with physical examinations and other clinical factors in the management of labor and delivery. [ABSTRACT FROM AUTHOR]

Background: Determining fetal head descent, expressed as fetal head station and engagement is an essential part of monitoring progression in labor. Assessing fetal head station is based on the distal part of the fetal skull, whereas assessing engagement is based on the proximal part. Prerequisites for assisted vaginal birth are that the fetal head should be engaged and its lowermost part at or below the level of the ischial spines. The part of the fetal head above the pelvic inlet reflects the true descent of the largest diameter of the skull. In molded (reshaped) fetal heads, the leading bony part of the skull may be below the ischial spines while the largest diameter of the fetal skull still remains above the pelvic inlet. An attempt at assisted vaginal birth in such a situation would be associated with risks. Therefore, the vaginal or transperineal assessments of station should be supplemented with a transabdominal examination. We suggest a method for the assessment of fetal head descent with transabdominal ultrasound.Objective: To investigate the correlation between transabdominal and transperineal assessment of fetal head descent, and to study fetal head shape at different labor stages and head positions.Study Design: Women with term singleton cephalic pregnancies admitted to the labor ward for induction of labor or in spontaneous labor, at the Cairo University Hospital and Oslo University Hospital from December 2019 to December 2020 were included. Fetal head descent was assessed with transabdominal ultrasound as the suprapubic descent angle between a longitudinal line through the symphysis pubis and a line from the upper part of the symphysis pubis extending tangentially to the fetal skull. We compared measurements with transperineally assessed angle of progression and investigated interobserver agreement. We also measured the part of fetal head above and below the symphysis pubis at different labor stages.Results: The study population comprised 123 women, of whom 19 (15%) were examined before induction of labor, 8 (7%) in the latent phase, 52 (42%) in the active first stage and 44 (36%) in the second stage. The suprapubic descent angle and the angle of progression could be measured in all cases. The correlation between the transabdominal and transperineal measurements was -0.90 (95% confidence interval, -0.86 to -0.93). Interobserver agreement was examined in 30 women and the intraclass correlation coefficient was 0.98 (95% confidence interval, 0.95-0.99). The limits of agreement were from -9.5 to 7.8 degrees. The fetal head was more elongated in occiput posterior position than in non-occiput posterior positions in the second stage of labor.Conclusion: We present a novel method of examining fetal head descent by assessing the proximal part of the fetal skull with transabdominal ultrasound. The correlation with transperineal ultrasound measurements was strong, especially early in labor. The fetal head was elongated in the occiput posterior position during the second stage of labor. [ABSTRACT FROM AUTHOR]

Background: Failure to progress is one of the leading indications for cesarean delivery in trials of labor in twin gestations. However, assessment of labor progression in twin labors is managed according to singleton labor curves.Objective: This study aimed to establish a partogram for twin deliveries that reflects normal and abnormal labor progression and customized labor curves for different subgroups of twin labors.Study Design: This was a multicenter, retrospective cohort analysis of twin deliveries that were recorded in 3 tertiary medical centers between 2003 and 2017. Eligible parturients were those with twin gestations at ≥34 weeks' gestation with cephalic presentation of the presenting twin and ≥2 cervical examinations during labor. Exclusion criteria were elective cesarean delivery without a trial of labor, major fetal anomalies, and fetal demise. The study group comprised twin gestations, whereas singleton gestations comprised the control group. Statistical analysis was performed using Python 3.7.3 and SPSS, version 27. Categorical variables were analyzed using chi-square tests. Student t test and Mann-Whitney U test were applied to analyze the differences in continuous variables, as appropriate.Results: A total of 1375 twin deliveries and 142,659 singleton deliveries met the inclusion criteria. Duration of the active phase of labor was significantly longer in twin labors than in singleton labors in both nulliparous and multiparous parturients; the 95th percentile duration was 2 hours longer in nulliparous twin labors and >3.5 hours longer in multiparous twin labors than in singleton labors. The cervical dilation progression rate was significantly slower in twin deliveries than in singleton deliveries with a mean rate in twin deliveries of 1.89 cm/h (95th percentile, 0.51 cm/h) and a mean rate of 2.48 cm/h (95th percentile, 0.73 cm/h) in singleton deliveries (P<.001). In addition, epidural use further slowed labor progression in twin deliveries. The second stage of labor was also markedly longer in twin deliveries, both in nulliparous and multiparous women (95th percentile, 3.04 vs 2.83 hours, P=.002).Conclusion: Twin labors are characterized by a slower progression of the active phase and second stage of labor compared with singleton labors in nulliparous and multiparous parturients. Epidural analgesia further slows labor progression in twin labors. Implementation of these findings in clinical management might lower cesarean delivery rates among cases with protracted labor in twin gestations. [ABSTRACT FROM AUTHOR]

Background: Physical activity in pregnancy is associated with decreased risks of adverse pregnancy outcomes such as gestational diabetes and preeclampsia. However, the relationship between the amount and type of physical activity during pregnancy and subsequent labor outcomes remains unclear.Objective: This study aimed to test the hypothesis that higher levels of physical activity across different lifestyle domains in pregnancy are associated with a shorter duration of labor.Study Design: This study is a secondary analysis of a prospective cohort study in which patients with singleton pregnancies without a major fetal anomaly were administered the Kaiser Physical Activity Survey in each trimester. The Kaiser Physical Activity Survey was designed specifically to quantify various types of physical activities in women and includes 4 summative indices-housework/caregiving, active living habits, sports, and occupation. The study included women at full-term gestations admitted for induction of labor or spontaneous labor. The primary outcome of this analysis was duration of the second stage of labor. Secondary outcomes were duration of the active stage, prolonged first and second stage, mode of delivery, rates of second-stage cesarean delivery, operative vaginal delivery, severe perineal lacerations, and postpartum hemorrhage. These outcomes were compared between patients with and without high physical activity levels, defined as overall Kaiser Physical Activity Survey score ≥75th percentile in the third trimester. Multivariable logistic regression was used to adjust for obesity and epidural use. In addition, a subgroup analysis of nulliparous patients was performed.Results: A total of 811 patients with complete Kaiser Physical Activity Survey data in the third trimester were included in this analysis. The median Kaiser Physical Activity Survey score was 9.5 (8.2-10.8). Of the 811 patients, 203 (25%) had higher levels of physical activity in pregnancy. There was no difference in the duration of the second stage of labor between patients with and without higher physical activity levels (1.29±2.94 vs 0.97±2.08 hours; P=.15). The duration of active labor was significantly shorter in patients with higher levels of physical activity (5.77±4.97 vs 7.43±6.29 hours; P=.01). Patients with higher physical activity levels were significantly less likely to have a prolonged first stage (9.8% vs 19.4%; P<.01; adjusted relative risk, 0.55; 95% confidence interval, 0.34-0.83). However, rates of prolonged second-stage cesarean delivery, operative vaginal deliveries, and perineal lacerations were similar between the 2 groups.Conclusion: Patients who are more physically active during pregnancy have a shorter duration of active labor. [ABSTRACT FROM AUTHOR]

Background: Persistent occiput posterior and occiput transverse positions are the most common malpositions of the fetal head during labor and are associated with prolonged second stage of labor, cesarean deliveries, instrumental deliveries, severe perineal tears, postpartum hemorrhage, and chorioamnionitis. Manual rotation is one of several strategies described to deal with these malpositions.Objective: This study aimed to determine if the trial of prophylactic manual rotation at the early second stage of labor is associated with a decrease in operative deliveries (instrumental and/or cesarean deliveries).Study Design: We conducted a multicenter, open-label, randomized controlled trial in 4 French hospitals. Women with singleton term pregnancy and occiput posterior or occiput transverse position confirmed by ultrasound at the early second stage of labor and with epidural analgesia were eligible. Women were randomly assigned (1:1) to either undergo a trial of prophylactic manual rotation of occiput posterior or occiput transverse position (intervention group) or no trial of prophylactic manual rotation (standard group). The primary outcome was operative delivery (instrumental and/or cesarean deliveries). The secondary outcomes were length of the second stage of labor, maternal complications (postpartum hemorrhage, operative complications during cesarean delivery, episiotomy and perineal tears), and neonatal complications (Apgar score of <5 at 10 minutes, arterial umbilical pH of <7.10, neonatal injuries, neonatal intensive care unit admission). The main analysis was focused on intention-to-treat analysis.Results: From December 2015 to December 2019, a total of 257 women (mean age, 30.4 years; mean gestational age, 40.1 weeks) were randomized: 126 were assigned to the intervention group and 131 were assigned to the standard group. Operative delivery was significantly less frequent in the intervention group compared with the standard group (29.4% [37 of 126] vs 41.2% [54 of 131]; P=.047; differential [intervention-standard] [95% confidence interval] = -11.8 [-15.7 to -7.9]; unadjusted odds ratio [95% confidence interval] = 0.593 [0.353-0.995]). Women in the intervention group were more likely to have a significantly shorter second stage of labor.Conclusion: Trial of prophylactic manual rotation of occiput posterior or occiput transverse positions during the early second stage of labor was statistically associated with a reduced risk of operative delivery. This maneuver could be a safe strategy to prevention operative delivery. [ABSTRACT FROM AUTHOR]

Background: Occiput posterior position is the most frequent cephalic malposition, and its persistence at delivery is associated with a higher risk of maternal and perinatal morbidity. Diagnosis and management of occiput posterior position remain a clinical challenge. This is partly caused by our inability to predict fetuses who will spontaneously rotate into occiput anterior from those who will have persistent occiput posterior position. The angle of progression, measured with transperineal ultrasound, represents a reliable tool for the evaluation of fetal head station during labor. The relationship between the persistence of occiput posterior position and fetal head station in the second stage of labor has not been previously assessed.Objective: This study aimed to evaluate the role of fetal head station, as measured by the angle of progression, in the prediction of persistent occiput posterior position and the mode of delivery in the second stage of labor.Study Design: We recruited a nonconsecutive series of women with posterior occiput position diagnosed by transabdominal ultrasound in the second stage of labor. For each woman, a transperineal ultrasound was performed to measure the angle of progression at rest. We compared the angle of progression between women who delivered fetuses in occiput anterior position and those with persistent occiput posterior position at delivery. Receiver operating characteristics curves were performed to evaluate the accuracy of the angle of progression in the prediction of persistent occiput posterior position. Finally, we performed a multivariate logistic regression to determine independent predictors of persistent occiput posterior position.Results: Overall, 63 women were included in the analysis. Among these, 39 women (62%) delivered in occiput anterior position, whereas 24 (38%) delivered in occiput posterior position (persistent occiput posterior position). The angle of progression was significantly narrower in the persistent occiput posterior position group than in women who delivered fetuses in occiput anterior position (118.3°±12.2° vs 127.5°±10.5°; P=.003). The area under the receiver operating characteristics curve was 0.731 (95% confidence interval, 0.594-0.869) with an estimated best cutoff range of 121.5° (sensitivity of 72% and specificity of 67%). On logistic regression analysis, the angle of progression was found to be independently associated with persistence of occiput posterior position (odds ratio, 0.942; 95% confidence interval, 0.889-0.998; P=.04). Finally, women who underwent cesarean delivery had significantly narrower angle of progression than women who had a vaginal delivery (113.5°±8.1 vs 128.0°±10.7; P<.001). The area under the receiver operating characteristics curve for the prediction of cesarean delivery was 0.866 (95% confidence interval, 0.761-0.972). At multivariable logistic regression analysis including the angle of progression, parity, and gestational age at delivery, the angle of progression was found to be the only independent predictor associated with cesarean delivery (odds ratio, 0.849; 95% confidence interval, 0.775-0.0930; P<.001).Conclusion: In fetuses with occiput posterior at the beginning of the second stage of labor, narrower values of the angle of progression are associated with higher rates of persistent occiput posterior position at delivery and a higher risk of cesarean delivery. [ABSTRACT FROM AUTHOR]

Background: No new method of assisting vaginal birth has been introduced into clinical practice since the development of the vacuum extractor in the 1950s. The Odon Device is a new device that employs a circumferential air cuff over the fetal head to assist birth. In this study, the Odon Device has been used to assist vaginal birth for standard clinical indications.Objective: This study aimed to investigate the clinical impact, safety, and acceptability of the Odon Device to women, their babies, and clinicians and to assess the feasibility of recruiting women to an interventional intrapartum research study.Study Design: This is a nonrandomized, single-arm interventional feasibility study of the Odon Device for operative vaginal birth undertaken in a single maternity unit: Southmead Hospital, Bristol, United Kingdom. The Odon Device was used to assist birth in 40 women who required the birth to be assisted for suspected fetal compromise and/or prolonged second stage of labor. The primary clinical outcome was the proportion of births successfully assisted with the Odon Device, and the primary feasibility outcome was the proportion of eligible women who were approached and who agreed to participate. Neonatal outcome data were reviewed at day 28, and maternal outcomes were investigated up to day 90.Results: Between October 2018 and January 2019, 298 of 384 approached, eligible women (77.6%) consented to participate. Of these women, 40 received the intervention-the use of the Odon Device. Birth was assisted in all cephalic (occiput anterior, occiput transverse, and occiput posterior) fetal positions, at all stations at or below the ischial spine and with or without regional analgesia. The Odon Device was effective in 19 of 40 cases (48%). Of the 40 births, 21 (52.5%) required additional assistance: 18 of 40 births (45%) were completed using nonrotational forceps, 1 of 40 births (3%) required rotational forceps, and 2 of 40 births (5%) required an emergency cesarean delivery. There was no serious maternal or neonatal adverse event related to the use of the device, and there was no serious adverse device effect. There were 4 devices (10%) that were ineffective because of a manufacturing fault. Furthermore, 39 of 40 women (98%) reported a high birth perception score. All practitioners were able to use the device as intended, although some steps in using the device were reported to be easier to perform (setup and deflation of air chamber) than others (application of the device and withdrawal of the applicator).Conclusion: Recruitment to an interventional study of a new device for operative vaginal birth was feasible; 78% of eligible women were willing to participate, often expressing an aspiration for an alternative to forceps and vacuum. The success rate of the Odon Device was lower than reported success rates of vacuum and forceps; however, in this study, the device had been used to assist birth for standard clinical indications. There was no significant maternal or neonatal safety concern associated with the use of the device, although the number of births studied was small. Further feasibility study to establish iterative changes to the device, technique, and clinical indications is necessary. [ABSTRACT FROM AUTHOR]

Background: Controversy surrounds the impact of the fetal head station on labor duration and mode of delivery. Although an extensive body of evidence has been published evaluating fetal head station in early labor, there is a paucity of data on the impact of fetal head descent during the second stage.Objective: This study aimed to explore the association between fetal head station at the diagnosis of the second stage of labor and the second stage duration and the risk of operative delivery.Study Design: This is a retrospective cohort study of all singleton vertex deliveries in a single tertiary center (2011-2016). Women were grouped according to fetal head station upon the diagnosis of the second stage of labor as follows: above (S<0), at the level (S=0), and below (S>0) the level of the ischial spine. The duration of the second stage and the risk of operative delivery were compared between the groups and stratified by parity.Results: Overall, 34,334 women met the inclusion criteria. Of these, 18,743 (54.6%) were nulliparous and 15,591 (45.4%) were multiparous. Of the nulliparous women, 8.1%, 35.8%, and 56.1% were diagnosed as having fetal head above, at the level, and below the ischial spine upon second stage diagnosis. Of the multiparous women, 19.7%, 35.6%, and 44.7% were diagnosed as having fetal head above, at the level, and below the ischial spine. Fetal head station upon second stage diagnosis was independently and significantly associated with second stage duration (P<.001); however, its contribution was 4.5-fold among nulliparous women compared with multiparous women. In multivariable analysis, after controlling for maternal age, gestational age at delivery, prepregnancy body mass index, epidural anesthesia, and birthweight, the risk of operative delivery was substantially increased in a dose-dependent pattern for both nulliparous and multiparous women.Conclusion: The fetal head station at the first diagnosis of the second stage is significantly and independently associated with the duration of the second stage and correlated with the risk of operative delivery in both nulliparous and multiparous women (P<.001). [ABSTRACT FROM AUTHOR]

Background: To accommodate passage through the birth canal, the fetal skull is compressed and reshaped, a phenomenon known as molding. The fetal skull bones are separated by membranous sutures that facilitate compression and overlap, resulting in a reduced diameter. This increases the probability of a successful vaginal delivery. Fetal position, presentation, station, and attitude can be examined with ultrasound, but fetal head molding has not been previously studied with ultrasound.Objective: This study aimed to describe ultrasound-assessed fetal head molding in a population of nulliparous women with slow progress in the second stage of labor and to study associations with fetal position and delivery mode.Study Design: This was a secondary analysis of a population comprising 150 nulliparous women with a single fetus in cephalic presentation, with slow progress in the active second stage with pushing. Women were eligible for the study when an operative intervention was considered by the clinician. Molding was examined in stored transperineal two-dimensional and three-dimensional acquisitions and differentiated into occipitoparietal molding along the lambdoidal sutures, frontoparietal molding along the coronal sutures, and parietoparietal molding at the sagittal suture (molding in the midline). Molding could not be classified if positions were unknown, and these cases were excluded. We measured the distance from the molding to the head midline, molding step, and overlap of skull bones and looked for associations with fetal position and delivery mode. The responsible clinicians were blinded to the ultrasound findings.Results: Six cases with unknown position were excluded, leaving 144 women in the study population. Fetal position was anterior in 117 cases, transverse in 12 cases, and posterior in 15 cases. Molding was observed in 79 of 144 (55%) fetuses. Molding was seen significantly more often in occiput anterior positions than in non-occiput anterior positions (69 of 117 [59%] vs 10 of 27 [37%]; P=.04). In occiput anterior positions, the molding was seen as occipitoparietal molding in 68 of 69 cases and as parietoparietal molding in 1 case with deflexed attitude. Molding was seen in 19 of 38 (50%) of occiput anterior positions ending with spontaneous delivery, 42 of 71(59%) ending with vacuum extraction, and in 7 of 8 (88%) with failed vacuum extraction (P=.13). In 4 fetuses with occiput posterior positions, parietoparietal molding was diagnosed, and successful vacuum extraction occurred in 3 cases and failed extraction in 1. Frontoparietal molding was seen in 2 transverse positions and 4 posterior positions. One delivered spontaneously; vacuum extraction failed in 3 cases and was successful in 2. Only 1 of 11 fetuses with either parietoparietal or frontoparietal molding was delivered spontaneously.Conclusion: The different types of molding can be classified with ultrasound. Occipitoparietal molding was commonly seen in occiput anterior positions and not significantly associated with delivery mode. Frontoparietal and parietoparietal moldings were less frequent than reported in old studies and should be studied in larger populations with mixed ethnicities. [ABSTRACT FROM AUTHOR]

Background: Vaginal birth is a risk factor for pubovisceral muscle tear, decreased urethral closure pressure, and urinary incontinence. The relationship between these 3 factors is complicated. Urinary continence relies on maintaining urethral closure pressure, particularly when low urethral closure pressure can usefully be augmented by a volitional pelvic muscle (Kegel) contraction just before and during stress events like a cough. However, it is unknown whether a torn pubovisceral muscle decreases the ability to increase urethral closure during an attempted pelvic muscle contraction.Objective: We tested the null hypothesis that a pubovisceral muscle tear does not affect the ability to increase urethral closure pressure during a volitional pelvic muscle contraction in the Evaluating Maternal Recovery from Labor and Delivery (EMRLD) study.Study Design: We studied 56 women 8 months after their first vaginal birth. All had at least 1 risk factor for pubovisceral muscle tear (eg, forceps and long second stage). A tear was assessed bilaterally by magnetic resonance imaging. Urethral closure pressure was measured both at rest and during an attempted volitional pelvic muscle contraction. A Student t test was used to compare urethral closure pressures. Multiple linear regression was used to estimate the effect of a magnetic resonance imaging-confirmed pubovisceral muscle tear on volitionally contracted urethral closure pressure after adjusting for resting urethral closure pressure.Results: The mean age was just a little more than 30 years, with the majority being white. By magnetic resonance imaging measure, unadjusted for other factors, the 21 women with tear had significantly lower urethral closure pressure during an attempted contraction compared with the 35 women without tear (65.9 vs 86.8 cm H2O, respectively, P = .004), leading us to reject the null hypothesis. No significant group difference was found in resting urethral closure pressure. After adjusting for resting urethral closure pressure, pubovisceral muscle tear was associated with lower urethral closure pressure (beta = -21.1, P = .001).Conclusion: In the first postpartum year, the presence of a pubovisceral muscle tear did not influence resting urethral closure. However, women with a pubovisceral muscle tear achieved a 25% lower urethral closure pressure during an attempted pelvic muscle contraction than those without a pubovisceral muscle tear. These women with pubovisceral muscle tear may not respond to classic behavioral interventions, such as squeeze when you sneeze or strengthen through repetitive pelvic muscle exercises. When a rapid rise to maximum urethral pressure is used as a conscious volitional maneuver, it appears to be reliant on the ability to recruit the intact pubovisceral muscle to simultaneously contract the urethral striated muscle. [ABSTRACT FROM AUTHOR]