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Enhanced communication between maternal-fetal medicine (MFM)/obstetrics and neonatology regarding counseling at extreme prematurity remains an essential element of prenatal consultations. Together, the obstetrician and neonatologist can collaborate to provide timely and synergistic information to affected couples during a dynamic period, combining their expertise to elucidate values and formulate a plan that best supports the pregnant person and partner’s goals. Such collaboration can help resolve differing perspectives between specialties, minimize redundancy and inconsistencies, and mitigate the impact of clinician bias. Best practices for joint-specialty collaboration include a precounseling clinician huddle, contemporaneous counseling by MFM specialists/obstetricians and neonatologists with the expectant parents or individualized sequential counseling if preferred by the couple, and a postcounseling clinician debrief. This approach can help establish a trusting relationship with families facing possible extremely preterm delivery and optimize the overall counseling experience. Future efforts focused on education and research, including a standardized approach to educational curricula among fellowship programs, should be emphasized.

Preeclampsia is a hypertensive disorder of pregnancy that is a leading cause of maternal and perinatal morbidity and mortality. The condition presents heterogeneously at varying gestational ages. Primary prevention for preeclampsia with low-dose aspirin is recommended for patients with clinical risk factors. Despite extensive research, there is no clearly defined pathophysiology for preeclampsia or treatment for preeclampsia besides delivery of the placenta. Delivery of patients with preeclampsia without severe features is indicated in the early term period at 37 weeks’ gestation and sooner if the patient develops severe preeclampsia. Management of preterm preeclampsia is guided by close assessment of the status of the pregnant woman and fetus, blood pressure control, and surveillance for any clinical progression to a more severe form of preeclampsia that may require preterm delivery. In a preterm gestation affected by preeclampsia, expectant management is intended to provide neonatal benefit though it does assume some maternal risk. Future research will hopefully further delineate the pathophysiology of the condition with the ultimate goal of finding a treatment to avoid associated morbidity and preterm delivery.

Objective:Patients with pregnancy-associated secondary brain tumors (PASBT) are challenging to manage. Because no guidelines for the management of such patients currently exist, we performed a systematic review of the literature using PRISMA guidelines with a discussion of management from a neurosurgeon’s perspective.Method:Systematic review of the literature using PRISMA guidelines from 1999 to 2018.Results:We identified 301 studies of which 16 publications (22 patients reporting 25 pregnancies, 20 deliveries, 5 early terminations) were suitable for final analysis. The most frequent primary cancers were breast (8/22, 36.36%), skin (6/22, 27.27%), and lung (5/22, 22.73%). Four patients (18.18%) had neurosurgical procedures during their pregnancies. Five patients (22.73%) received neurosurgical resection after their pregnancies. Nine patients (40.91%) received radiation therapy and seven patients (31.82%) received chemotherapy during pregnancy while seven patients (31.82%) received chemotherapy and radiation after pregnancy. There was 1 fetal death (5%) out of 20 healthy deliveries. Five pregnancies (20%) were terminated in the first trimester due to a need for urgent neurosurgical intervention.Conclusion:Management of PASBT remains a challenging issue. Maternal and fetal risks associated with surgical resection and teratogenicity due to adjuvant therapy should be discussed in the context of a multidisciplinary team. Timing of surgery and the use of systemic chemoradiation depends on the gestational age (GA) of the fetus, extent, and control of the mother’s primary and metastatic disease. Guidelines need to be established to help neuro-oncology teams safely and effectively manage this group of patients.

Objectives To provide an overview of perinatal outcomes in prenatally diagnosed spontaneous chorioamniotic separation (sCAS). Methods A systematic search of the literature was performed from inception to July 2019, including PubMed, Ovid MEDLINE, and Ovid EMBASE. All studies reporting prenatally diagnosed sCAS after 16 weeks' gestation in singleton pregnancies were eligible. Two independent reviewers used standardized forms for data abstraction. Results Of 408 screened abstracts, 17 studies reporting 118 cases of sCAS were included. Among 113 cases with delivery outcomes, preterm birth (PTB) occurred in 60 (53.1%, 95% confidence interval [CI] 43.9-62.3%). Intrauterine fetal demise (IUFD) occurred in seven (6.2%, 95% CI 1.8-10.6%) cases, with four due to cord strangulation. Spontaneous abortion occurred in one (0.88%, 95% CI -0.84-2.6%) case. Among 104 cases with postnatal follow-up, there were six (5.8%, 95% CI 1.3-10.3%) neonatal deaths and one (0.96%, 95% CI -0.91-2.8%) infant death. Perinatal mortality (IUFD and neonatal deaths) was 11.0% (95% CI 5.4-16.7%). Conclusions sCAS may be associated with increased risk of PTB, however, the available data are largely case reports and series. Antepartum surveillance after viability can be considered due to risk of cord accidents. Prospective study is necessary to understand the clinical implications of sCAS.

The optimal management of Chiari I malformation during pregnancy remains uncertain. Labor contractions, which increase intracranial pressure, and neuraxial anesthesia both carry the theoretical risk of brainstem herniation given the altered CSF dynamics inherent to the condition. Mode of delivery and planned anesthesia, therefore, require forethought to avoid potentially life-threatening complications. Since the assumed potential risks are significant, we seek to systematically review published literature regarding Chiari I malformation in pregnancy and, therefore, to establish a best practice recommendation based on available evidence. The English-language literature was systematically reviewed from 1991 to 2018 according to PRISMA guidelines to assess all pregnancies reported in patients with Chiari I malformation. After analysis, a total of 34 patients and 35 deliveries were included in this investigation. Additionally, a single case from our institutional experience is presented for illustrative purposes but not included in the statistical analysis. No instances of brain herniation during pregnancy in patients with Chiari I malformation were reported. Cesarean deliveries (51%) and vaginal deliveries (49%) under neuraxial blockade and general anesthesia were both reported as safe and suitable modes of delivery. Across all publications, only one patient experienced a worsening of neurologic symptoms, which was only later discovered to be the result of a previously undiagnosed Chiari I malformation. Several patients underwent decompressive suboccipital craniectomy to treat the Chiari I malformation during the preconception period (31%), during pregnancy (3%), and after birth (6%). Specific data regarding maternal management were not reported for a large number (21) of these patients (60%). Aside from one abortion in our own institutional experience, there was no report of any therapeutic abortion or of adverse fetal outcome. Although devastating maternal complications are frequently feared, very few adverse outcomes have ever been reported in pregnant patients with a Chiari I malformation. The available evidence is, however, rather limited. Based on our survey of available data, we recommend vaginal delivery under neuraxial blockade for truly asymptomatic patients. Furthermore, based on our own experience and physiological conceptual considerations, we recommend limiting maternal Valsalva efforts either via Cesarean delivery under regional or general anesthesia or by choosing assisted vaginal delivery under neuraxial blockade. There is no compelling reason to offer suboccipital decompression for Chiari I malformation during pregnancy. For patients with significant neurologic symptoms prior to conception, decompression prior to pregnancy should be considered.

What is the association between polycystic ovary syndrome (PCOS) and pre-eclampsia? Data suggest that patients with PCOS are at increased risk of developing pre-eclampsia; however, several studies have not found an independent association between the two.A retrospective case-control study of singleton deliveries at a tertiary care hospital from 2011 to 2015. Patients with pre-eclampsia (cases) were matched to the next delivery without pre-eclampsia (controls) on gestational age week. Medical history data, a diagnosis or clinical features of PCOS and obstetric data, including pre-eclampsia, were abstracted from the medical record. Groups were compared with the chi-squared test, and conditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (95% CI). OR were adjusted for maternal age at delivery and race/ethnicity.This study included 435 cases and 435 controls. Cases were more likely to be Black compared with controls. Age, comorbidities, features of PCOS and use of IVF were similar between groups. Patients with pre-eclampsia were not more likely to have PCOS (8.3%) than those without pre-eclampsia (6.2%, adjusted OR 1.40, 95% CI 0.81-2.30). Sensitivity analyses for body mass index and parity suggested an increased pre-eclampsia risk for patients with PCOS and these additional factors, however no group showed a statistically significant association between PCOS and pre-eclampsia.In this study, a history of PCOS was not associated with the risk of pre-eclampsia. Further investigation is necessary to determine whether there are subgroups of PCOS patients who are at increased risk of pre-eclampsia.

This article provides a summary of a landmark study in obstetrics. The article provides insight on a pivotal question; Is delivery before 39 weeks among patients undergoing elective repeat cesarean delivery associated with increased risk of adverse neonatal outcomes? The authors describe the basics of the study, including study location, study population, number of patients, study design, endpoints, results, and limitations. The article briefly reviews other relevant studies and information, discusses implications, and concludes with a relevant clinical case. The article places these finding in contemporary context and highlights its impact on obstetric care. In addition, the author reference updated national guidelines developed as a result of this study.

Objectives Ischemic placental disease (IPD), including preeclampsia, abruption, and fetal growth restriction, often recurs in subsequent pregnancies. Angiogenic factors of placental origin have been implicated in the pathogenesis of preeclampsia, but have not been studied as predictors of IPD in subsequent pregnancies. We hypothesized that elevated angiogenic factors in an index pregnancy would be associated with recurrence of IPD. Study design We conducted a retrospective cohort study of patients undergoing evaluation for preeclampsia who had angiogenic factors measured in an index pregnancy and experienced a subsequent pregnancy at the same institution. Patients with IPD in the index pregnancy were included. A high ratio of soluble fms-like tyrosine kinase 1 (sFlt1) and placental growth factor (PlGF) was defined as greater than or equal to 85. Main outcome measures The primary outcome was IPD in a subsequent pregnancy. Results We included 109 patients in the analysis. The sFlt1/PlGF ratio was elevated in 30% of participants. Those with an elevated ratio were more likely to be nulliparous in the index pregnancy, and less likely to have chronic hypertension. The recurrence of IPD in the study was 27%, with a non-significant difference in risk based on a high sFlt-1/P1GF ratio RR 0.58 (95% CI 0.21 – 1.6) compared to a low ratio. Conclusions A high sFlt1/P1GF ratio in an index pregnancy is not associated with a higher risk of IPD in a subsequent pregnancy. These data suggest placental angiogenic biomarkers are specific to the pregnancy and not a reflection of maternal predisposition to IPD.

Objective To evaluate the association between in vitro fertilization (IVF) and ischemic placental disease (IPD), stratified by gestational age. Design We performed a secondary analysis of a retrospective cohort study of deliveries. Setting Deliveries were performed over 15 years at a single tertiary hospital. Patient(s) We included all parturients who had a live born infant or an intrauterine fetal demise (IUFD). Intervention(s) We compared pregnancies resulting from IVF cycles to non-IVF pregnancies. Main Outcome Measure(s) The primary outcomes were preterm and term IPD (preeclampsia, placental abruption, small-for-gestational age infant [SGA], or an intrauterine fetal demise [IUFD] due to placental insufficiency). Result(s) Of the 69,084 deliveries during the study period, 3,763 (5.4%) were conceived with IVF. The incidence of preterm delivery was 32.6% in IVF pregnancies and 10.8% in non-IVF pregnancies. Multiple gestations were more common in IVF pregnancies. Compared to non-IVF pregnancies, IVF pregnancies were more likely to develop both preterm and term IPD, even after adjustment for maternal age and parity. The risk of preterm IPD was 4 times higher (95% confidence interval, 3.7–4.4) in patients who underwent IVF compared with those who did not undergo IVF. Among parturients who delivered at ≥37 weeks of gestation, IVF pregnancies had 1.7 times the risk of term IPD (95% confidence interval, 1.6–1.9) compared with non-IVF pregnancies. Conclusion(s) IVF was strongly associated with preterm IPD. We found a similar, but attenuated, association between IVF and term IPD. The stronger association with preterm IPD suggests an association between IVF and placental insufficiency.

AIM Fetal membranes are composed of the amnion and chorion, which fuse during the early second trimester. Persistent separation confers increased risk of adverse perinatal outcomes. This study characterizes sonographic and placental findings associated with persistent amnion-chorion (AC) membrane separation. METHODS This is a case series of 23 patients carrying singleton pregnancies with persistent AC membrane separation after 16 weeks' gestation diagnosed by ultrasound from 2010 to 2016 at our institution. Twenty placentas were available for analysis. RESULTS Obstetrical complications occurred in 13 (56.5%) cases; two (8.7%) cases resulted in intrauterine fetal demise. Fetal malformations were reported in eight (34.8%) cases. Four (17.4%) neonates were small-for-gestational age (SGA

Stroke in pregnant women has a mortality rate of 1.4 deaths per 100,000 deliveries. Vascular malformations are the most common cause of hemorrhagic stroke in this population; preeclampsia and other risk factors have been identified. However, nearly a quarter of strokes have an undeterminable cause. Spontaneous intracranial hemorrhage (ICH) is less frequent but results in significant morbidity. The main objective of this study is to review the literature on pregnant patients who had a spontaneous ICH. A systematic review of the literature was conducted on PubMed and the Cochrane library from January 1992 to September 2016 following the PRISMA guidelines. Studies reporting pregnant patients with spontaneous intraparenchymal hemorrhage (IPH), subarachnoid hemorrhage (SAH), and subdural hemorrhage (SDH) were selected and included if patients had non-structural ICH during pregnancy or up to 6 weeks postpartum confirmed by imaging. Twenty studies were included, and 43 patients identified. Twenty-two patients (51.3%) presented with IPH, 15 patients (34.8%) with SAH, and five patients (11.6%) with SDH. The most common neurosurgical management was clinical in 76.7% of patients, and cesarean section was the most common obstetrical management in 28% of patients. The most common maternal outcome was death (48.8%), and fetal outcomes were evenly distributed among term delivery, preterm delivery, and fetal or neonatal death. Spontaneous ICH carries a high maternal mortality with IPH being the most common type, most frequently presenting in the third trimester. Diagnosis and management do not differ for the parturient compared to the non-pregnant woman.

A pregnant woman undergoes increased fetal ultrasonographic surveillance during the pregnancy for an amnion-chorion separation and fetal growth restriction. At 34 weeks’ gestation, an ultrasound finding prompts the recommendation for a preterm delivery. Video 1 shows the placental finding seen after an uncomplicated delivery of a late preterm infant. This finding can increase a neonate’s risk of which of the following? Video 1 Click here to view the video. Placental findings in this case that are consistent with the presence of amniotic bands. Video 2 provides commentary of the placental findings in this case, which are consistent with the presence of amniotic bands. Amniotic bands are fibrous strands that separate from the amniotic sac. Frequently they are not visualized postnatally but may result …

There is a strong correlation between the level of circulating female sex hormones and the parturient growth of meningiomas. As a result, rapid changes in meningioma size occur during pregnancy, putting both the mother and fetus at risk. Large, symptomatic meningiomas require surgical resection, regardless of the status of pregnancy. However, the preferred timing of such complex intervention is a matter of debate. The rarity of this clinical scenario and the absence of prospective trials make it difficult to reach evidence-based conclusions. The aim of this study was to create evidence-based management guidelines for timing of surgery for pregnancy-related intracranial meningiomas. The English literature from 1990 to 2016 was systematically reviewed according to PRISMA guidelines for all surgical cases of pregnancy–related intracranial meningiomas. Cases were divided into two groups: patients who have had surgery during pregnancy and delivered thereafter (group A) and patients who delivered first (group B). Groups were compared for demographic, clinical and radiological features, as well as for neurosurgical, obstetrical and neonatological outcomes. Statistical analysis was performed to assess differences. A total of 104 surgical cases were identified and reviewed, of which 86 were suitable for comparison and statistical analysis. Thirty-five patients (40%) underwent craniotomy for resection during pregnancy or at delivery (group A) and 51 patients (60%) underwent surgery after delivery (group B). Groups showed no significant differences in characteristics such as age at diagnosis, number of gestations, presenting symptoms, tumor site and tumor size. Despite a comparable distribution over the gestational trimesters, group A had significantly more patients diagnosed prior to the 27th gestational week (46 vs 17.5%, p = 0.0075). Group A was also associated with a significantly higher rate of both emergent craniotomies (40 vs 19.6%, p = 0.0048) and emergent Caesarian deliveries (47 vs 17.8%, p = 0.00481). The time from diagnosis to surgery was significantly longer in group B (11 weeks vs 1 week in group A, p = 0.0013). The rate of premature delivery was high but similar in both groups (∼70%). Risks of maternal mortality or fetal mortality were associated with group A (odds ratio = 14.7), but did not reach statistical significance. While surgical resection of meningioma during pregnancy may be associated with increased maternal and fetal mortalities, the overall neurosurgical, obstetrical and neonatological outcomes, as well as many clinical characteristics, are similar to patients undergoing resection postpartum. We believe that fetal survival chances have a significant impact on decision-making, as patients diagnosed at a later stage in pregnancy (≥27th week of gestation) were more likely to undergo delivery first. This complicated clinical scenario requires the close cooperation of multiple disciplines. While the mother’s health and well-being should always be paramount in guiding management, we hope that the overall good outcomes observed by this systematic review will encourage colleagues to aim for term pregnancies whenever possible in order to reduce prematurity-related problems.

Intrapartum care encompasses the treatment of pregnancy during labor and delivery. Knowledge of the normal labor process is essential to effectively recognize and treat abnormalities, and thus optimize maternal and fetal health. This review aims to outline the physiology of labor and discuss contemporary features of spontaneous labor, prolonged labor, and arrest of labor. It addresses management of group B streptoccocous colonization and electronic fetal monitoring practices. Additionally, issues associated with term labor such as prelabor rupture of membranes, abruption, intrapartum intraamniotic infection, and persistent occiput posterior position are discussed. The review concludes with a brief overview of delivery methods. This review contains 7 figures, 14 tables, and 49 references. Keywords: term labor, intrapartum monitoring, induction of labor, Group B Streptococcous prophylaxis, prelabor rupture of membranes, intraamniotic infection, mode of delivery

PURPOSE: Assess the risk of ischemic placental disease (IPD) among in vitro fertilization (IVF; donor and autologous) pregnancies compared with non-IVF pregnancies. METHODS: This was a retrospective cohort study of deliveries from 2000 to 2015 at a tertiary hospital. The exposures, donor, and autologous IVF, were compared with non-IVF pregnancies and donor IVF pregnancies were also compared with autologous IVF pregnancies. The outcome was IPD (preeclampsia, placental abruption, small for gestational age (SGA), or intrauterine fetal demise due to placental insufficiency). We defined SGA as birthweight

OBJECTIVE: To compare the incidence of Group B Streptococcus (GBS) conversion from a negative antepartum to a positive intrapartum culture among women who self-identify as non-Hispanic black, Hispanic, or non-Hispanic white. STUDY DESIGN: This was a prospective cohort study of women with a negative rectovaginal GBS culture within 35 days of enrollment. An intrapartum rectovaginal swab was collected and cultured for GBS. Data were compared with chi-square, Fisher’s exact, or Wilcoxon rank-sum test. Modified Poisson regression was used. RESULTS: We enrolled 737 women; 75.4% were non-Hispanic white, 17.6% were non-Hispanic black, and 6.9% were Hispanic. Non-Hispanic black women were more likely to convert to GBS positive than non-Hispanic white women, 9.2% as compared to 5.3% (RR: 2.0; 95% CI: 1.02–3.8). CONCLUSION: The increased incidence of positive intrapartum GBS cultures among non-Hispanic black women suggests that non-Hispanic black race is a risk factor for GBS conversion in the late third trimester.

Stroke in pregnant women has a mortality rate of 1.4 deaths per 100,000 deliveries. Vascular malformations are the most common cause of hemorrhagic stroke in this population; preeclampsia and other risk factors have been identified. However, nearly a quarter of strokes have an undeterminable cause. Spontaneous intracranial hemorrhage (ICH) is less frequent but results in significant morbidity. The main objective of this study is to review the literature on pregnant patients who had a spontaneous ICH. A systematic review of the literature was conducted on PubMed and the Cochrane library from January 1992 to September 2016 following the PRISMA guidelines. Studies reporting pregnant patients with spontaneous intraparenchymal hemorrhage (IPH), subarachnoid hemorrhage (SAH), and subdural hemorrhage (SDH) were selected and included if patients had non-structural ICH during pregnancy or up to 6 weeks postpartum confirmed by imaging. Twenty studies were included, and 43 patients identified. Twenty-two patients (51.3%) presented with IPH, 15 patients (34.8%) with SAH, and five patients (11.6%) with SDH. The most common neurosurgical management was clinical in 76.7% of patients, and cesarean section was the most common obstetrical management in 28% of patients. The most common maternal outcome was death (48.8%), and fetal outcomes were evenly distributed among term delivery, preterm delivery, and fetal or neonatal death. Spontaneous ICH carries a high maternal mortality with IPH being the most common type, most frequently presenting in the third trimester. Diagnosis and management do not differ for the parturient compared to the non-pregnant woman.

In pregnancy, the majority of women experience at least some nausea and vomiting. For many women, these symptoms are mild and self-limiting and resolve by the second trimester. A minority of women experience severe symptoms of hyperemesis gravidarum with persistent vomiting, weight loss, and electrolyte derangements. The diagnosis of hyperemesis gravidarum is based on clinical history and exclusion of other etiologies of nausea and vomiting. First-line pharmacologic treatment is with pyridoxine and doxylamine. Other medical treatments include metoclopramide, phenothiazines, antacids, and ondansetron. In refractory cases, corticosteroids and enteral or parenteral nutrition may be considered. This review contains 3 figures, 2 tables and 83 references Key words: enteral feeding, hyperemesis gravidarum, maternal outcomes, nausea and vomiting of pregnancy, neonatal outcomes, nonpharmacologic antiemetics, pharmacologic antiemetics

Objective: Admissions to acute care hospitals represent a significant portion of healthcare utilization. Little is known regarding hospitalization in the first postpartum year beyond the traditional 6 weeks of the puerperium. We sought to investigate whether there are identifiable risk factors for hospital readmission during this time period. Study Design: We conducted a retrospective population-based study using all California birth records between 1999 and 2003. These records were linked with hospital discharge data for all admissions to California hospitals in the first 365 days after delivery. For women with a first birth during the study period, we assessed the likelihood of readmission to an acute care hospital between 42 and 365 days post-delivery. Univariate and multivariable logistic regression were used to determine risk factors for these “late postpartum” admissions. Results: Of 951,570 maternal birth admissions during the time period, 15,727 (1.7%) women were admitted in the late postpartum period. Women with an early postpartum readmission, antepartum admission, extremes of maternal age, black race, diabetes, hypertension, early preterm delivery and cesarean delivery had higher rates of late postpartum readmission. Of women with an antepartum admission for gestational diabetes or pre-existing diabetes, 6.6% and 18.5% of these women experienced a late postpartum admission for a diabetes-related diagnosis. Conclusion: Hospital readmission rates in the first year postpartum, remote from delivery, are significant. Women are at a higher risk of requiring hospital admission in the first year postpartum with select demographics and pregnancy-related diagnoses.

In medical school, students learn that the diagnostic criteria for preeclampsia are new-onset hypertension and proteinuria after 20 weeks of gestation. An accurate diagnosis is essential, because preeclampsia is a leading cause of iatrogenic prematurity; the sole known “cure” for preeclampsia is delivery of the placenta. However, in clinical practice, the diagnosis of preeclampsia may be more nuanced than the classic textbook presentation. In a subset of patients, severe preeclampsia and even eclampsia (i.e., the presence of seizures) may present atypically in the absence of either hypertension or proteinuria. Diagnosing preeclampsia is further complicated by the fact that signs and symptoms of preeclampsia overlap with those of other medical conditions seen in pregnancy, such as liver disease, renal disease, chronic hypertension, and idiopathic thrombocytopenic purpura. Moreover, the standard clinical diagnostic criteria, such as hypertension or proteinuria, are not sufficiently accurate to predict adverse outcomes associated with the disease. The American College of Obstetricians and Gynecologists recently released new guidelines modifying the diagnostic criteria for preeclampsia that broaden the inclusion criteria to further reflect the heterogeneity of the clinical presentation (1). Current emphasis on overdiagnosis may improve maternal outcomes but may also lead to worse neonatal outcomes, because iatrogenic preterm delivery could result from significant misclassification of the disease. Preeclampsia is a leading cause of maternal mortality in developed and developing countries, making an improved diagnostic tool that is linked to the pathogenesis of the disease an important goal and a crucial step toward developing new treatments. Basic research has implicated a major pathogenic role for angiogenic imbalance in the placenta in the onset and progression of preeclampsia. High circulating concentrations of antiangiogenic factors such as soluble fms-like tyrosine kinase 1 (sFlt1)3 and low concentrations of proangiogenic factors such as placental growth factor (PlGF) released by the placenta contribute to …

To evaluate the effect of placenta previa location (anterior vs posterior) on cesarean morbidity.Retrospective cohort of women undergoing cesarean for placenta previa. The rate of hysterectomy and blood transfusion in the setting of anterior previa was compared with posterior previa. Planned stratified analysis based on delivery history was performed. Logistic regression was performed to control for potential confounders.Two hundred and eighty-five women undergoing cesarean delivery for placenta previa were identified. Women undergoing primary cesareans with an anterior previa had higher rates of blood transfusion (adjusted odds ratio (aOR) 3.13 95% confidence interval (CI) (1.18 to 8.36) and hysterectomy (7.4% vs 0, P=0.001) compared with those with a posterior previa; similarly, women undergoing repeat cesarean with anterior previa had higher rates of hysterectomy (aOR 4.60 95% CI (1.02 to 20.7). The majority of hysterectomies (93.8%) were due to abnormal placentation.An anterior placenta previa increases the risk of hysterectomy for both primary and repeat cesareans due to abnormal placentation. In the absence of accreta, blood transfusion remained a significant cause of maternal morbidity in both anterior and posterior placenta previas. This information may be useful for operative planning.

Background Our goal is to study triggers of spontaneous preterm delivery using a case-crossover design.