Rosalind Janik

Vaginal birth after cesarean: New insights on maternal and neonatal outcomes

OBJECTIVE: 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.

New Insights on Vaginal Birth After Cesarean: Can It Be Predicted?

OBJECTIVE: To evaluate existing vaginal birth after cesarean (VBAC) screening tools and to identify additional factors that may predict VBAC or failed trial of labor. DATA SOURCES: Relevant studies were identified through MEDLINE, Database of Abstracts of Reviews of Effectiveness, and the Cochrane databases (1980-September 2009), and from recent systematic reviews, reference lists, reviews, editorials, web sites, and experts. METHODS OF STUDY SELECTION: Inclusion criteria limited studies to those of humans, written in English, studies conducted in the United States and developed countries, and those rated good or fair quality by the U.S. Preventive Services Task Force criteria. Studies of individual predictors were combined using a random effects model when the estimated odds ratios were comparable across included studies. TABULATION, INTEGRATION, AND RESULTS: We identified 3,134 citations and reviewed 963 papers, of which 203 met inclusion criteria and were quality-rated. Twenty-eight provided evidence on predictors of VBAC and 16 presented information on scored models for predicting VBAC (or failed trial of labor). Six of the 11 scored models for predicting VBAC (or failed trial of labor) were validated by separated dataset, cross-validation, or both. Whereas accuracy remained high across all models for predicting VBAC, with predictive values ranging from 88% to 95%, accuracy for predicting failed trial of labor was low, ranging from 33% to 58%. Individual predictors including Hispanic ethnicity, African-American race, advanced maternal age, no previous vaginal birth history, birth weight heavier than 4 kg, and use of either augmentation or induction were all associated with reduced likelihood of VBAC. CONCLUSION: Current scored models provide reasonable predictability for VBAC, but none provides consistent ability to identify women at risk for failed trial of labor. A scoring model is needed that incorporates known antepartum factors and can be adjusted for current obstetric factors and labor patterns if induction or augmentation is needed. This would allow women and clinicians to better determine individuals most likely to require repeat cesarean delivery.

Trial of Labor and Vaginal Delivery Rates in Women with a Prior Cesarean

OBJECTIVE To evaluate evidence on trial of labor (TOL) and vaginal delivery rates in women with a prior cesarean and to understand the characteristics of women offered a trial of labor. DATA SOURCES MEDLINE, DARE, and Cochrane databases were searched for articles evaluating mode of delivery for women with a prior cesarean delivery published between 1980 and September 2009. STUDY SELECTION Studies were included if they involved human participants, were in English, conducted in the United States or in developed countries, and if they were rated fair or good base on U.S. Preventive Services Task Force (USPSTF) criteria. DATA EXTRACTION AND SYNTHESIS The search yielded 3,134 abstracts: 69 full-text papers on TOL and vaginal birth after cesarean (VBAC) rates and 10 on predictors of TOL. The TOL rate in U.S. studies was 58% (95% CI [52, 65]) compared with 64% (95% CI [59, 70]) in non U.S. STUDIES The TOL rate in the U.S. was 62% (95% CI [57, 66]) for studies completed prior to 1996 and dropped to 44% (95% CI [34, 53]) in studies launched after 1996, p = .016. In U.S. studies, 74% (95% CI [72, 76]) of women who had a TOL delivered vaginally. Women who had a prior vaginal birth or delivered at a large teaching hospital were more likely to be offered a TOL. CONCLUSIONS Although the TOL rate has dropped since 1996, the rate of vaginal delivery after a TOL has remained constant. Efforts to increase rates of TOL will depend on patients understanding the risks and benefits of both options. Maternity providers are well positioned to provide key education and counseling when patients are not informed of their options.