A National Institutes of Health (NIH) consensus panel has issued recommendations that pregnant women and their care providers use evidence-based decision making to determine whether a trial of labor and possible vaginal birth after cesarean section (VBAC) would be appropriate. The panel also urged the medical community to reduce barriers to women who want to try a VBAC.

Controversy about VBAC gained prominence in 1980, when an NIH consensus panel issued a report challenging the prevailing practice that women who undergo cesarean section (C-section) must deliver all subsequent children that way. Following the issuance of this report, the number of VBAC’s rose through the early 1990s. However, VBAC has steadily decreased since 1996, while C-sections have increased.

Approximately 75% of women succeed in having a vaginal delivery after previous cesarean delivery, assuming that it is not a multiple birth, that the baby is in the normal position, and that their previous cesarean section required only a single incision. However, women who might want to give labor a try sometimes do not get a chance. Some hospital policies will not allow VBAC unless the facility is fully equipped and has surgical and anesthesia services readily available. These policies align with current guidelines set by gynecology and anesthesia professional societies.

The 15-member consensus panel found varying degrees of evidence of harm to the mother or fetus following a trial of labor. For example, they found moderate evidence for a “clear increased risk of uterine rupture in trial of labor compared to an elective repeat cesarean delivery.” On the other hand, they found a low level of evidence regarding the factors that increase the risk of uterine rupture, such as “classical” and low vertical uterine scars or a history of two or more prior cesareans.

The panel found moderate evidence of a decreased risk of abnormal placental position in women who underwent a successful trial of labor. It also found only low-grade evidence of harm accruing from a trial of labor, such as an increased risk of pelvic floor disorders.

As for risks to the baby with a trial of labor, the panel found moderate evidence of increased perinatal mortality and low-grade evidence of increased fetal mortality, as well as insufficient data on the incidence of hypoxic ischemic encephalopathy in cases of VBAC versus repeat cesarean sections.

While acknowledging that there is much to learn about which women are ideal candidates for VBAC, the panel agreed that women’s desires and preferences be respected throughout the decision-making process.

1. National Institutes of Health (NIH) [website]. National Institutes of Health Consensus Development Conference Statement. NIH Consensus Development Conference. Vagina Birth After Cesarean: New Insights. March 19, 2010. Available at: http://consensus.nih.gov/2010/images/vbac/vbac_statement.pdf. Accessed March 19, 2010.

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This entry was posted on Friday, March 19th, 2010 at 12:00 pm.