Search

Asynclitism is malposition and malpresentation of the head in the pelvis. It is shown that asynclitism during the configuration (molding) of the head leads to an uneven distribution of the tension forces of the tentorium cerebelli (TC) and to its one-sided ruptures, mainly in the left half. It is indicated that with asynclitism larger more than 15 mm (moderate degree of asynclitism), the risk of birth trauma to the skull and brain increases. It was shown that not only severe degree of asynclitism, but also a moderate degree are pathological due to possible complications. The data on the sonographic diagnosis of asynclitism are presented. The negative effects of vacuum extraction (VE), the forceps application are considered. The mechanism of subaponeurotic hemorrhages is described. The importance of timely asynclitism diagnosis in labor to prevent its complication is shown. The cesarean section is practiced as extreme solution to the problem. The widespread use of sonography for the asynclitism diagnosis will prevent the birth trauma and reduce the incidence of mobility and mortality of the children and mother. [ABSTRACT FROM AUTHOR]

Objective: To construct an ultrasound partogram using serial transperineal sonographic measurements of the angle of fetal head progression during the first stage of labor, and to compare it with a conventional partogram based on digital vaginal examinations. Methods: Between 2017 and 2018, a prospective cohort study at Drum Tower Hospital, Nanjing, China, recruited 375 nulliparous women with singleton pregnancy and spontaneous onset of labor at 37 or more gestational weeks. Transperineal ultrasound scans were performed to measure the angle of progression (AoP) every 0.5–1 h until the second stage. Vaginal examinations were also used to measure cervical dilatation. Repeated‐measures analysis was used to generate labor curves. Results: The labor curve generated by AoP had a pattern similar to that based on cervical dilatation. There was an initial slow period lasting approximately 5.5 h until the cervical dilatation or AoP reached the inflection point (4 cm and 119°, respectively), followed by a second, more rapid period, lasting approximately 2.5 h. Conclusion: Based on ultrasound data, it was feasible to construct an "angle of progression partogram" of the first stage of labor, which was similar in pattern to the partogram based on cervical dilatation measured in the same cohort. Synopsis: The labor curve generated from the angle of progression of the fetal head had a pattern similar to that based on cervical dilatation by vaginal examination. [ABSTRACT FROM AUTHOR]

Background: The research and advances in obstetrics are performed to overcome abnormal vaginal deliveries. The obstetrician's skill using digital vaginal examination (DVE) remains a personal skill with limitations. Objective: Assessment of the ability of intrapartum ultrasound capability to observe the progression of normal labor in the first stage compared to DVE accurately and objectively. Patients and methods: This prospective cohort study, was conducted on 62 singleton pregnancies in their 38-40 weeks of pregnancy at Obstetrics and Gynecology ultrasound unit and Maternity Hospital, during a period between 2018 to 2020. All cases received clinical examination including, general, abdominal, and obstetrical examination and ultrasonography examination including, transvaginal, transabdominal, and transperineal. Result: The transvaginal ultrasound evaluated the rate of cervical dilatation at the first stage of labor and the length of the cervix showed a statistically significant negative correlation and statistically significant positive correlation between time of labor progress at first and cervical length. There was statistically significantly higher mean cervical dilatation by DVE than US findings (4.58 & 4.29, respectively). Conclusion: Ultrasound usage possesses a potential role in predicting vaginal delivery success and helping the promotion of safe operative delivery. [ABSTRACT FROM AUTHOR]

Fetal malpresentation, malposition, and asynclitism are among the most common determinants of a protracted active phase of labor, arrest of dilatation during the first stage, and arrest of descent in the second stage. The diagnosis of these conditions is traditionally based on vaginal examination, which is subjective and poorly reproducible. Intrapartum sonography has been demonstrated to yield higher accuracy than vaginal examination in characterizing fetal malposition, and some guidelines endorse its use for the verification of the occiput position before performing an instrumental delivery. It is also useful for the objective diagnosis of the malpresentation or asynclitism of the fetal head. According to our experience, the sonographic assessment of the head position in labor is simple to perform also for clinicians with basic ultrasound skills, whereas the assessment of malpresentation and asynclitism warrants a higher level of expertise. When clinically appropriate, the fetal occiput position can be easily ascertained using transabdominal sonography combining the axial and the sagittal planes. With the transducer positioned on the maternal suprapubic region, the fetal head can be visualized, and landmarks including the fetal orbits, the midline, and the occiput itself with the cerebellum and the cervical spine (depending on the type of fetal position) can be demonstrated below the probe. Sinciput, brow, and face represent the 3 "classical" variants of cephalic malpresentation and are characterized by a progressively increasing degree of deflexion from vertex presentation. Transabdominal sonography has been recently suggested for the objective assessment of the fetal head attitude when a cephalic malpresentation is clinically suspected. Fetal attitude can be evaluated on the sagittal plane with either a subjective or an objective approach. Two different sonographic parameters such as the occiput-spine angle and the chin-chest angle have been recently described to quantify the degree of flexion in fetuses in non-occiput-posterior or occiput-posterior position, respectively. Finally, although clinical examination still represents the mainstay of diagnosis of asynclitism, the use of intrapartum sonography has been shown to confirm the digital findings. The sonographic diagnosis of asynclitism can be achieved in expert hands using a combination of transabdominal and transperineal sonography. At suprapubic sonography on the axial plane only, 1 orbit can be visualized (squint sign) while the sagittal suture appears anteriorly (posterior asynclitism) or posteriorly (anterior asynclitism) displaced. Eventually the transperineal approach does not allow the visualization of the cerebral midline on the axial plane if the probe is perpendicular to the fourchette. In this expert review we summarize the indications, technique, and clinical role of intrapartum sonographic evaluation of fetal head position and attitude., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: Cervical assessment during digital vaginal examination (DVE) includes assessing cervical dilatation, effacement, position and consistency. Only cervical dilatation during labor has been previously researched. We investigated cervical changes, including cervical dilatation and effacement, using a wireless ultrasound (US) device.Materials and Methods: This was a longitudinal study investigating cervical changes during labor using a wireless US device. Twenty-five women in labor participated in a serial comparison of cervical dilatation, length and thickness measured during intrapartum transperineal sonography using a wireless mobile US device (SONON) with measurements of cervical dilatation and effacement obtained during serial DVEs.Results: Intrapartum sonography showed strong correlation with DVE in assessing cervical changes during labor including the measurement of cervical dilatation and thickness (p < .001). The failure rate of cervical length image collection was high; therefore, we could not determine the correlation between cervical length and effacement.Conclusions: We developed a new technique for evaluating effacement with cervical thickness. Cervical dilation and thickness using a transperineal intrapartum US demonstrated significant correlation with DVE findings. The use of a wireless US device is convenient and may be advantageous in the labor ward; however, further research is needed to define the role of this wireless device. [ABSTRACT FROM AUTHOR]

Background: During the second stage of labor, in case of a need for a fetal extraction at midcavity, the choice of attempting the procedure between operative vaginal delivery and cesarean delivery is difficult. Moreover, guidelines on this subject are not clear., Objective: This study aimed to identify antenatal and intrapartum parameters associated with a failed midcavity vacuum-assisted delivery and its association with maternal and neonatal adverse outcomes., Study Design: This was a single-center, retrospective, cohort study conducted at a tertiary maternity hospital in France from January 2010 to December 2020. Women with singleton pregnancies under epidural analgesia with nonanomalous cephalic presenting fetuses and gestational ages at ≥37 weeks of gestation, who were submitted to midcavity vacuum-assisted delivery, were included. Following the American College of Obstetricians and Gynecologists definition, midcavity was defined as the presenting part of the fetus (ie, the fetal head) found at stations 0 and +1. For research purposes, all patients were submitted to transperineal ultrasound to evaluate the head-to-perineum distance, however, this measurement did not affect the decision to perform a midcavity vacuum-assisted delivery. The primary outcome of the study was failed midcavity vacuum-assisted delivery leading to cesarean delivery or the use of a different instrument to achieve vaginal delivery., Results: Overall, 951 cases of midcavity vacuum-assisted delivery were included in this study. Failed midcavity vacuum-assisted delivery occurred in 242 patients (25.4%). Factors independently associated with failed midcavity vacuum-assisted delivery included maternal height (adjusted odds ratio, 0.96; 95% confidence interval, 0.94-0.99; P=.002), duration of the active phase of the first stage of labor (adjusted odds ratio, 1.11; 95% confidence interval, 1.05-1.17; P<.001), nonocciput anterior fetal head position (adjusted odds ratio, 1.47; 95% confidence interval, 1.06-2.04; P=.02), z score of the head-to-perineum distance (adjusted odds ratio, 1.23; 95% confidence interval, 1.05-1.43; P=.01), and birthweight of >4000 g (adjusted odds ratio, 2.04; 95% confidence interval, 1.28-3.26; P=.003). Women submitted to a failed midcavity vacuum-assisted delivery were more likely to have a major postpartum hemorrhage (7.1% vs 2.0%; P<.001), whereas neonates were more likely to have an umbilical artery pH of <7.1 (30.5% vs 19.8%; P=.001), be admitted to the neonatal intensive care unit (9.6% vs 4.7%; P=.005), and have a severe caput succedaneum (14.9% vs 0.7%; P<.001). Subgroup analysis on all patients with a fetal head station of 0 found that the head-to-perineum distance was the only independent variable associated with failed midcavity vacuum-assisted delivery (adjusted odds ratio, 1.66; 95% confidence interval, 1.29-2.12; P<.001). The area under the receiving operating characteristic curve of the head-to-perineum distance in this subgroup population was 0.67 (95% confidence interval, 0.60-0.73; P<.001), and the optimal cutoff point of the head-to-perineum distance measurement discriminating between failed and successful midcavity vacuum-assisted deliveries was 55 mm. It was associated with a 0.90 (95% confidence interval, 0.83-0.95) sensitivity, 0.19 (95% confidence interval, 0.14-0.25) specificity, 0.36 (95% confidence interval, 0.30-0.42) positive predictive value, and 0.80 (95% confidence interval, 0.66-0.90) negative predictive value., Conclusion: Study data showed that a high fetal head station, measured using the head-to-perineum distance, and a nonocciput anterior position of the fetal head are independently associated with failed midcavity vacuum-assisted delivery. The result supported the systematic assessment of the sonographic head station and position before performing a midcavity vacuum-assisted delivery., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Fetal head progression during labor is difficult to assess. Digital examination has been shown to be an inaccurate method. Utilizing the ultrasound technology in the delivery room can standardize the way we assess head progression. Intrapartum ultrasound is applicable, for the assessment of the progression of labor and assists the obstetrician, in decision making regarding the need for an assisted delivery. This article summarizes the latest studies regarding the usage of ultrasound in the delivery room and the measurements that are used during delivery. [ABSTRACT FROM AUTHOR]

Objective To evaluate the clinical significance of fetal head progression distance (HPD), measured by transperineal ultrasound, during prolonged second stage of labor. Methods In this prospective study, a single operator, who was blinded to the results of the digital examination, assessed using transperineal ultrasound women at ≥ 37 weeks of gestation with failure to progress in the second stage of labor. Patients had an empty urinary bladder and the examination was performed during maternal pushing. HPD was defined as the length of the line perpendicular to the infrapubic line that would connect it to the lowest part of the fetal bony skull. We analyzed associations between HPD and digital examination of fetal head station, fetomaternal characteristics, mode of delivery and perinatal outcome. Results Sixty-five patients in prolonged second stage of labor participated in the study. The overall mean HPD was 6.50 (± 1.35; 95% CI, 6.16-6.83) cm. No correlation was found between HPD and head position or mode of delivery, but HPD was positively correlated with fetal head station and neonatal head circumference measured after delivery. Logistic regression and receiver-operating characteristics curve analysis demonstrated no significant predictive value of HPD with respect to mode of delivery. Conclusion Although HPD in prolonged second stage of labor could not predict mode of delivery, it may have a role as an ancillary tool for fetal head station assessment. [ABSTRACT FROM AUTHOR]

Objective: The primary goal of this study was to determine the ultrasonographic signs of asynclitic and transverse head positioning. In addition, we compared the performance of intrapartum ultrasound to vaginal digital examination. Material & Methods: 150 women were evaluated by 2D transabdominal and translabial ultrasound (US) to detect the asynclitic and deep transverse positions. Transvaginal sterile digital examinations were performed immediately after each intrapartum US assessments, the examinations were repeated at intervals of 45-90 minutes. Examiners were blinded to each other's findings (clinical or sonographic). Data were reviewed and analyzed by an independent reviewer. Results: The efficacy of digital examination was significantly lower than US evaluation for the detection of either transverse position or asynclitism. The most frequent transverse position was the left one, while the most frequent asynclitism was the anterior one. Conclusions: Digital pelvic examination for detection of fetal head transverse position during labor is inferior to US, especially in the deep transverse positioning, where caput succedaneum occurs and reduces the diagnostic accuracy of vaginal digital examination. The US examination leads to early detection of persistent transverse position allowing for earlier timing and optimal technique for the operative vaginal delivery. We describe two signs for diagnosing asynclitism. The 'squint sign' and the 'sunset of thalamus and cerebellum signs' are two simple US signs allowing detection of anterior and posterior asynclitism. [ABSTRACT FROM AUTHOR]

Purpose: To investigate if early epidural analgesia can influence fetal head engagement into the pelvis and if it can increase the rate of transverse and asynclitic position during labour. Materials and Methods: 195 women with combined spinal-epidural analgesia (CSE) or without neuraxial analgesia were studied. CSE was performed using a mixture of ropivacaine 0.02% with 0.3 µg/ml of sufentanil administered in the spinal space. Maintenance of analgesia was managed with intermittent epidural administration of 10-15 ml of ropivacaine (0.07%-0.10%) mixed with 0.5 µg/ml of sufentanil, based on the stage of labour and the degree of pain. 2D transabdominal ultrasound (US) was used. Serial transabdominal US examinations were performed at 45-90 min intervals to detect transverse and asynclitic positions, using the following signs: squint sign, sunset thalamus and cerebellum signs that best details the fetal head station. After delivery, the complete set of clinical and US data obtained by each examination were recorded and compared in women with and without labour analgesia. Data were examined by independent reviewers. Results: There was no difference in obstetric outcome between women in whom CSE had been used and those who did not request analgesia during labour (p>0.05). Conclusions: Epidural analgesia initiated early during labour and using low doses does not increase the rate of dystocic labors. Transverse fetal head positioning with anterior or posterior asynclitism does not seem to be promoted by drug or technique-related mechanisms, but rather should be the consequence of cephalopelvic disproportion. [ABSTRACT FROM AUTHOR]

Assessment of cervical dilatation by digital vaginal examination is commonly used during labor as one of the main indicators of labor progress. Despite consistent inaccuracies, this practice remains widely chosen among midwives and obstetricians. Several methods, including electromechanical and electromagnetic devices, have been trialed throughout the decades without being able to provide objective means of obtaining accurate measurements of cervical dilatation during labor. Intrapartum ultrasound in the form of transperineal or translabial applications has shown promising results in the assessment and monitoring of labor progress. Here, we described the validity of intrapartum ultrasound and its usefulness in the assessment of cervical dilatation during labor. Moreover, we highlighted the feasibility of ultrasound in obtaining these assessments., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Fetuses with malpresentation and malposition during labor represent important clinical challenges. Women with fetuses presenting with malpresentation or malposition are at risk of increased perinatal complications, such as cesarean delivery, failure of operative vaginal delivery, neonatal acidemia, and neonatal intensive care admission. Intrapartum ultrasound has been found to be more reliable than digital examination in assessing malpresentation and malposition. The use of intrapartum ultrasound to assess fetal position and presentation, in addition to fetal attitude, to predict and aid in decision making regarding delivery can help in improving management decision making. Cephalic malpresentation and malposition is a unique subset of fetal orientation and can benefit from intrapartum ultrasound identification and assessment for delivery., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Fetal head asynclitism may affect labor progress, increase the need for obstetrical intervention, and even be associated with difficult or failed instrumental delivery. However, there is limited evidence on the true prevalence and associations of asynclitism when diagnosed by transperineal ultrasound in the second stage of labor., Objective: This study aimed to examine the prevalence and outcome of asynclitism in the second stage of labor in a regional hospital in Hong Kong., Study Design: This is a prospective cohort study involving 92 term nulliparous women with singleton pregnancy in the second stage of labor, recruited from December 2019 to December 2020. Transperineal ultrasound was performed and asynclitism was diagnosed if there was asymmetry of intracranial structures on the transverse plane. To assess the fetal head station, the head perineum distance was measured at rest and on pushing, and the mode of delivery was recorded. Relationship between asynclitism and fetal head position, and between head perineum distance and the mode of delivery, were evaluated with chi-squared tests and Mann-Whitney U tests., Results: The prevalence of asynclitism was 15% (14 of 92), of which 12 were anterior asynclitism and 2 were posterior asynclitism. The prevalence of asynclitism was less common in occiput anterior compared with nonocciput anterior position (6.7% vs 53%, P<.01). Women with asynclitism were associated with smaller delta head perineum distance (head perineum distance at rest minus that at pushing) than women without asynclitism (median [interquartile range], 0.68 cm [0.85 cm] vs 0.91 cm [0.71 cm]; P=.01). Eventually, there was a trend of more operative deliveries in women with asynclitism (43%, or 6 of 14 women) than in women without asynclitism (27%, or 21 of 78 women), although this difference was not statistically significant (P=.22)., Conclusion: The prevalence of asynclitism at transperineal ultrasound was rather common in nulliparous women at second stage of labor and seemed more commonly associated with nonocciput anterior position., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Malpositions and deflexed cephalic malpresentations are well recognized causes of dysfunctional labor, may result in fetal and maternal complications, and are diagnosed more precisely with an ultrasound examination than with a digital examination., Objective: This study aimed to assess the incidence of malpositions and deflexed cephalic malpresentations at the beginning of the second stage of labor and to evaluate the role of the sonographic diagnosis of deflexion in the prediction of the mode of delivery., Study Design: Women in labor with a singleton pregnancy at term with fetuses in a cephalic presentation at 10 cm of cervical dilatation were prospectively examined. A transabdominal ultrasound was performed to assess the fetal head position by demonstrating the fetal occiput or the eyes. Deflexion was assessed by the measurement of the occiput-spine angle when the occiput was anterior or transverse and by qualitative assessment of the relationship between chin and thorax when the occiput was posterior. Transperineal ultrasound was performed in occiput posterior fetuses to discriminate between sinciput, brow, and face presentation. Maternal, labor, and neonatal parameters including maternal age, induction of labor, use of epidural, birthweight, arterial pH, and neonatal intensive care unit admission were recorded. Patients were divided into 2 groups according to the sonographic diagnosis of head deflexion. Adjusted odds ratios were calculated using multivariate logistic regression to determine the association between cesarean delivery and the 2 groups. In addition, labor and neonatal characteristics were compared between occiput anterior and occiput posterior-occiput transverse fetuses., Results: Of the 200 women at the beginning of the second stage, the fetus was in occiput anterior position in 156 (78%), transverse in 11 (5.5%), and posterior in 33 (16.5%) cases. Deflexion was diagnosed in 33 of 156 (21.2%) occiput anterior fetuses and 19 of 44 (43.2%) occiput posterior and occiput transverse fetuses. Cesarean deliveries were significantly associated with fetal head deflexion both in occiput anterior (P=.001) and occiput posterior (P<.001) fetuses. Sonographic diagnosis of fetal head deflexion was an independent risk factor for cesarean delivery both in occiput anterior (adjusted odds ratio, 5.37; 95% confidence interval, 1.819-15.869) and occiput posterior (adjusted odds ratio, 13.9; 95% confidence interval, 1.958-98.671) cases, and it was an independent risk factor for cesarean delivery regardless of the occiput position (adjusted odds ratio, 5.83; 95% confidence interval, 2.47-13.73)., Conclusion: The sonographic diagnosis of fetal head deflexion at the beginning of the second stage increases the risk of cesarean delivery., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objectives: The aim of the study is to determine the usefulness of ultrasound parameters in the second stage of labor in prediction of the method of delivery and to evaluate the benefits to be derived from this study., Material and Methods: Ultrasound scan was performed with Convex transabdominal probe on 68 pregnant women in labor at term with fetuses in cephalic presentation at the beginning of the second stage of labor and parameters such as angle of progression, head progression distance, head-symphysis distance and head-perineum distance were measured. The parameters were observed in two scans: a midline scan visualizing the pubic symphysis with the head of the fetus and a transverse scan approximately 1-2 cm below the pubic symphysis visualizing the head of the fetus., Results: The ultrasound parameters measured at the beginning of the second stage of labor, differed in the group in which women have delivered vaginally and in the group, in which caesarean section was performed: angle of progression and head progression distance were greater in group of women who delivered naturally and head-perineum distance and head-symphysis distance were smaller in this group. Some relations between each measured parameter and time left to delivery were observed as well as strong relations among parameters were also observed., Conclusions: Intrapartum sonography is a useful and objective tool to assess the progress of labor. Transperineal ultra-sound scans performed in the second stage of labor may play a role in making the decision about the mode of delivery.