To systematically review the evidence about maternal and neonatal outcomes relating to vaginal birth after cesarean (VBAC). DATA SOURCES: Relevant studies were identified from multiple searches of MEDLINE, DARE, and the Cochrane databases (1980 to September 2009) and from recent systematic reviews, reference lists, reviews, editorials, Web sites, and experts. METHODS OF STUDY SELECTION: Inclusion criteria limited studies to the English-language and human studies conducted in the United States and developed countries specifically evaluating birth after previous cesarean delivery. Studies focusing on high-risk maternal or neonatal conditions, including breech vaginal delivery, or fewer than 10 patients were excluded. Poor-quality studies were not included in analyses. TABULATION, INTEGRATION, AND
Results
We identified 3,134 citations and reviewed 963 articles for inclusion; 203 articles met the inclusion criteria and were quality rated. Overall rates of maternal harms were low for both trial of labor and elective repeat cesarean delivery. Although rare in both elective repeat cesarean delivery and trial of labor, maternal mortality was significantly increased for elective repeat cesarean delivery at 0.013% compared with 0.004% for trial of labor. The rates of maternal hysterectomy, hemorrhage, and transfusions did not differ significantly between trial of labor and elective repeat cesarean delivery. The rate of uterine rupture for all women with prior cesarean was 0.30%, and the risk was significantly increased for trial of labor (0.47% compared with 0.03% for elective repeat cesarean delivery). Perinatal mortality was also significantly increased for trial of labor (0.13% compared with 0.05% for elective repeat cesarean delivery).
Conclusion
Overall the best evidence suggests that VBAC is a reasonable choice for the majority of women. Adverse outcomes were rare for both elective repeat cesarean delivery and trial of labor. Definitive studies are lacking to identify patients who are at greatest risk for adverse outcomes.
American College of Obstetricians and Gynecologists et al., 2018·Obstetrics & Gynecology
Placenta accreta spectrum, formerly known as morbidly adherent placenta, refers to the range of pathologic adherence of the placenta, including placenta increta, placenta percreta, and placenta accreta. The most favored hypothesis regarding the etiology of placenta accreta spectrum is that a defect of the endometrial-myometrial interface leads to a failure of normal decidualization in the area of a uterine scar, which allows abnormally deep placental anchoring villi and trophoblast infiltration. Maternal morbidity and mortality can occur because of severe and sometimes life-threatening hemorrhage, which often requires blood transfusion. Although ultrasound evaluation is important, the absence of ultrasound findings does not preclude a diagnosis of placenta accreta spectrum; thus, clinical risk factors remain equally important as predictors of placenta accreta spectrum by ultrasound findings. There are several risk factors for placenta accreta spectrum. The most common is a previous cesarean delivery, with the incidence of placenta accreta spectrum increasing with the number of prior cesarean deliveries. Antenatal diagnosis of placenta accreta spectrum is highly desirable because outcomes are optimized when delivery occurs at a level III or IV maternal care facility before the onset of labor or bleeding and with avoidance of placental disruption. The most generally accepted approach to placenta accreta spectrum is cesarean hysterectomy with the placenta left in situ after delivery of the fetus (attempts at placental removal are associated with significant risk of hemorrhage). Optimal management involves a standardized approach with a comprehensive multidisciplinary care team accustomed to management of placenta accreta spectrum. In addition, established infrastructure and strong nursing leadership accustomed to managing high-level postpartum hemorrhage should be in place, and access to a blood bank capable of employing massive transfusion protocols should help guide decisions about delivery location.
Pregnancy Complications · Premature Rupture of Membranes
Hsu JZ et al., 2025·Eur J Obstet Gynecol Reprod Biol·
Endometriosis is a chronic gynaecological condition affecting reproductive-aged women. It has been associated with infertility and potential risks for adverse pregnancy outcomes, although population-level evidence remains limited. This retrospective cohort study, including 147,950 pregnant women aged 20-45 years, used nationwide population-based data to compare the outcomes between women with (n = 11,400) and without (n = 136,550) endometriosis between 2000 and 2021. Baseline characteristics, comorbidities and pregnancy outcomes were compared between the groups. Multivariable regression analyses were performed to calculate adjusted relative risks (aRR) and 95 % confidence intervals (CI) for various pregnancy outcomes, and subgroup analyses were conducted by maternal age and infertility status. Among 147,950 pregnancies, women with endometriosis [mean ± standard deviation (SD) age 32.38 ± 4.51 years] had higher socio-economic status, more comorbidities, and more surgical history compared with women without endometriosis (mean ± SD age 30.06 ± 4.96 years). Women with endometriosis had increased risk of miscarriage (aRR 1.13, 95 % CI 1.03-1.24), preterm birth (aRR 1.31, 95 % CI 1.26-1.37), premature rupture of membranes (aRR 1.11, 95 % CI 1.06-1.16), placenta previa (aRR 1.63, 95 % CI 1.45-1.84), urinary tract infection (aRR 1.44, 95 % CI 1.31-1.59), and caesarean section (aRR 1.13, 95 % CI 1.11-1.16). Subgroup analysis revealed that risk of miscarriage was only higher in women aged 35-45 years and women without infertility. Risks of preterm birth, placenta previa and caesarean section were elevated across all subgroups, suggesting that endometriosis contributes independently to adverse pregnancy outcomes. Endometriosis is an independent risk factor for several pregnancy complications, supporting the need for tailored prenatal care and closer monitoring of affected women to improve maternal outcomes.
Solmonovich R et al., 2025·Fertility and sterility
To determine whether an association exists between in vitro fertilization (IVF) and severe maternal morbidity among low-risk pregnant patients. Retrospective cohort study. Low-risk pregnant patients who delivered between January 2019 and December 2022. Low-risk was defined as having an obstetric comorbidity index score of 0. In vitro fertilization. MAIN OUTCOME MEASURE(S): The primary outcome (dependent variable) was any severe maternal morbidity. The secondary outcome was the need for a cesarean delivery. A modified Poisson regression with robust error variance was used to model the probability of severe maternal morbidity as a function of IVF. Risk ratios and their associated 95% confidence intervals (CIs) were computed. An α value of 0.05 was considered statistically significant. RESULT(S): A total of 39,668 pregnancies were included for analysis, and 454 (1.1%) were conceived by IVF. The overall severe maternal morbidity rate was 2.4% (n = 949), with the most common indicator being blood transfusion. The overall cesarean delivery rate was 18.8% (n = 7,459). On modified Poisson regression, IVF-conceived pregnancies were associated with 2.56 times the risk of severe maternal morbidity (95% CI, 1.73-3.79) and 1.54 times the risk of having a cesarean delivery (95% CI, 1.37-1.74) compared with non-IVF pregnancies. CONCLUSION(S): In vitro fertilization is associated with higher rates of severe maternal morbidity, primarily the need for a blood transfusion, and cesarean delivery in low-risk pregnancies without major comorbidities. Recognizing this association allows healthcare providers to implement proactive measures for better monitoring and tailored postpartum care.
Young-Wolff KC et al., 2024·JAMA internal medicine
Many studies have evaluated whether in utero cannabis exposure is associated with fetal and neonatal outcomes, yet little is known about whether prenatal cannabis use is associated with maternal health outcomes during pregnancy. To evaluate whether prenatal cannabis use is associated with maternal health outcomes during pregnancy. DESIGN, SETTING, This population-based retrospective cohort study included pregnancies in Northern California from January 2011 to December 2019 that lasted 20 weeks or longer and were screened for prenatal cannabis use. Prenatal cannabis use was defined as any self-reported use during early pregnancy or a positive toxicology test result based on universal screening at entrance to prenatal care (approximately 8-10 weeks' gestation). Self-reported frequency of use (daily, weekly, monthly or less, never, unknown), use defined only by self-report, and use defined only by toxicology test results were examined. Electronic health record data were used to define the following outcomes: gestational hypertension, preeclampsia, eclampsia, gestational diabetes, gestational weight gain greater and less than guidelines, placenta previa, placental abruption, placenta accreta, and severe maternal morbidity. Adjusted risk ratios (aRRs) were calculated using a modified Poisson regression. The sample (n = 316 722 pregnancies; 250 221 unique individuals) included 84 039 (26.5%) Asian/Pacific Islander, 20 053 (6.3%) Black, 83 145 (26.3%) Hispanic, and 118 333 (37.4%) White individuals; the mean (SD) age was 30.6 (5.4) years. Overall, 20 053 (6.3%) screened positive for prenatal cannabis use; 2.9% were positive by self-report, 5.3% by toxicology testing, and 1.8% by both. The frequency of cannabis use was 1930 (0.6%) daily, 2345 (0.7%) weekly, 4892 (1.5%) monthly or less, and 10 886 (3.4%) unknown. Prenatal cannabis use was associated with greater risk of gestational hypertension (aRR, 1.17; 95% CI, 1.13-1.21), preeclampsia (aRR, 1.08; 95% CI, 1.01-1.15), weight gain less than (aRR, 1.05; 95% CI, 1.01-1.08) and greater than (aRR, 1.09; 95% CI, 1.08-1.10) guidelines, and placental abruption (aRR, 1.19; 95% CI, 1.05-1.36). The pattern of results was similar when defining prenatal cannabis use only by self-report or only by toxicology testing, and associations between the frequency of prenatal cannabis use and outcomes varied with outcome. The results of this cohort study suggest that prenatal cannabis use was associated with several adverse maternal health outcomes during pregnancy. Continued research is needed to understand whether characteristics of prenatal cannabis use (eg, dose, mode, and timing) moderate these associations.