NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.

Cover of Vaginal Birth After Cesarean: New Insights

Vaginal Birth After Cesarean: New Insights

Evidence Reports/Technology Assessments, No. 191

Investigator Team: , MD, MPH, , PhD, , PhD, CNM, , MD, , MD, , PhD, , BA, , MA, , MA, and , PharmD.

Oregon Evidence-based Practice Center, Oregon Health & Science University, Portland, Oregon
Rockville (MD): Agency for Healthcare Research and Quality (US); .
Report No.: 10-E003

Structured Abstract

Objectives:

To synthesize the published literature on vaginal birth after cesarean (VBAC). Specifically, to review the trends and incidence of VBAC, maternal benefits and harms, infant benefits and harms, relevant factors influencing each, and the directions for future research.

Data Sources:

Relevant studies were identified from multiple searches of MEDLINE®; DARE; the Cochrane databases (1966 to September 2009); and from recent systematic reviews, reference lists, reviews, editorials, Web sites, and experts.

Review Methods:

Specific inclusion and exclusion criteria were developed to determine study eligibility. The target population includes healthy women of reproductive age, with a singleton gestation, in the U.S. with a prior cesarean who are eligible for a trial of labor (TOL) or elective repeat cesarean delivery (ERCD). All eligible studies were quality rated and data were extracted from good or fair quality studies, entered into tables, summarized descriptively and, when appropriate, pooled for analysis. The primary focus of the report was term pregnancies. However, due to a small number of studies on term pregnancies, general population studies including all gestational ages (GA) were included in appropriate areas.

Results:

We identified 3,134 citations and reviewed 963 papers for inclusion, of which 203 papers met inclusion and were quality rated. Studies of maternal and infant outcomes reported data based upon actual rather than intended router of delivery. The range for TOL and VBAC rates was large (28–82 percent and 49–87 percent, respectively) with the highest rates being reported in studies outside of the U.S. Predictors of women having a TOL were having a prior vaginal delivery and settings of higher-level care (e.g., tertiary care centers). TOL rates in U.S. studies declined in studies initiated after 1996 from 63 to 47 percent, but the VBAC rate remained unimproved. Hispanic and African American women were less likely than their white counterparts to have a vaginal delivery. Overall rates of maternal harms were low for both TOL and ERCD. While rare for both TOL and ERCD, maternal mortality was significantly increased for ERCD at 13.4 per 100,000 versus 3.8 per 100,000 for TOL. The rates of maternal hysterectomy, hemorrhage, and transfusions did not differ significantly between TOL and ERCD. The rate of uterine rupture for all women with prior cesarean is 3 per 1,000 and the risk was significantly increased with TOL (4.7/1,000 versus 0.3/1,000 ERCD). Six percent of uterine ruptures were associated with perinatal death. No models have been able to accurately predict women who are more likely to deliver by VBAC or to rupture. Women with a prior cesarean delivery had a statistically significant increased risk of placenta previa compared with women with no prior cesarean, at a rate of 12 per 1,000 and risk increasing with the number of cesareans. Women with one prior cesarean and previa had a statistically significant increased risk of adverse events compared with previa patients without a prior cesarean delivery: blood transfusion (15 versus 32.2 percent), hysterectomy (0.7 to 4 percent versus 10 percent), and composite maternal morbidity (15 versus 23–30 percent). Perinatal mortality was significantly increased for TOL at 1.3 per 1,000 versus 0.5 per 1,000 for ERCD. Insufficient data were found on nonmedical factors such as medical liability, economics, hospital staffing, structure and setting, which all appear to be important drivers for VBAC.

Conclusions:

Each year 1.5 million childbearing women have cesarean deliveries, and this population continues to increase. This report adds stronger evidence that VBAC is a reasonable and safe choice for the majority of women with prior cesarean. Moreover, there is emerging evidence of serious harms relating to multiple cesareans. Relatively unexamined contextual factors such as medical liability, economics, hospital structure, and staffing may need to be addressed to prioritize VBAC services. There is still no evidence to inform patients, clinicians, or policy-makers about the outcomes of intended route of delivery because the evidence is based largely on the actual route of delivery. This inception cohort is the equivalent of intention to treat for randomized controlled trials and this gap in information is critical. A list of future research considerations as prioritized by national experts is also highlighted in this report.

Contents

540 Gaither Road, Rockville, MD 20850. www​.ahrq.gov

Prepared for: Agency for Healthcare Research and Quality, U.S. Department of Health and Human Services.1 Contract No. 290-2007-10057-I. Prepared by: Oregon Evidence-based Practice Center, Oregon Health & Science University, Portland, Oregon.

Suggested citation:

Guise J-M, Eden K, Emeis C, Denman MA, Marshall N, Fu R, Janik R, Nygren P, Walker M, McDonagh M. Vaginal Birth After Cesarean: New Insights. Evidence Report/Technology Assessment No.191. (Prepared by the Oregon Health & Science University Evidence-based Practice Center under Contract No. 290-2007-10057-I). AHRQ Publication No. 10-E003. Rockville, MD: Agency for Healthcare Research and Quality. March 2010.

This information is based on research conducted by the Oregon Evidence-based Practice Center (EPC) under contract to the Agency for Healthcare Research and Quality (AHRQ), Rockville, MD (Contract No. 290-2007-10057-I). The findings and conclusions in this document are those of the authors, who are responsible for its content, and do not necessarily represent the views of AHRQ. No statement in this report should be construed as an official position of AHRQ or of the U.S. Department of Health and Human Services.

The information in this report is intended to help clinicians, employers, policymakers, and other make informed decisions about the provision of health care services. This report is intended as a reference and not as a substitute for clinical judgment.

This report may be used, in whole or in part, as the basis for development of clinical practice guidelines and other quality enhancement tools, or a basis for reimbursement and coverage policies. AHRQ or U.S. Department of Health and Human Services endorsement of such derivative products may not be stated or implied.

No investigators have any affiliations or financial involvement (e.g., employment, consultancies, honoraria, stock options, expert testimony, grants or patents received or pending, or royalties) that conflict with material presented in this report.

1

540 Gaither Road, Rockville, MD 20850. www​.ahrq.gov

Bookshelf ID: NBK44571
PubReader format: click here to try

Views

Related information

Related citations in PubMed

See reviews...See all...

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...