Vaginal birth after caesarean, or VBAC, is reasonably safe and should be more widely available, a National Institutes of Health advisory panel concluded Wednesday.
Such deliveries once accounted for 25% of U.S. births among women with a previous caesarean delivery, but have now fallen to less than 9%. Many women would like to attempt a vaginal delivery, however, and the panel's consensus statement is expected to increase their access to the option.
The panel, composed of independent experts in maternal and child health, found that although both VBAC and planned, repeat caesareans posed a range of risks and benefits, women should be allowed more choice. Thus, nonmedical deterrents such as hospital policies, legal liability concerns and doctor preferences should be dismantled, it said.
"The tide is to walk away from VBAC. But the panel is making a clear statement that we need to understand and better address the nonmedical barriers to VBAC," said Carol Sakala, director of programs for Childbirth Connection, a national nonprofit organization that works to improve maternity care. "They want to give women the option of VBAC."
The statement was released at the conclusion of a three-day meeting in Bethesda, Md., to reassess the scientific evidence on VBAC safety, taking into account women's and doctors' attitudes.
The U.S. caesarean delivery rate has risen 50% since 1996 and now stands at a record high of 31.8% of all births, and a policy of repeating caesareans once a woman has had one has contributed significantly to that climb. Federal health authorities have suggested the primary C-section rate should be about half of what it is now.
VBAC fell out of favor over the last 15 years because of criticism that it was performed too often, especially among women at high risk for complications. The most serious risk of VBAC is that the uterus will tear along the scar left by the previous caesarean delivery. A uterine rupture, which occurs in about 0.8% of women having their first VBAC, can be life-threatening.
Evidence presented this week found that an unsuccessful VBAC attempt -- labor that concludes with a C-section -- has a higher rate of complications than a planned repeat caesarean. Almost 75% of women who attempt vaginal delivery after a prior C-section do so successfully, although the panel noted that there was no way to predict who would be successful.
"One of the major goals of our panel was to be able to provide individual women with information on risk," said Dr. Emily Spencer Lukacz, an associate professor of clinical reproductive medicine at UC San Diego. "Each individual woman will have different preferences and different levels of risk they are willing to accept in order to have the experience they are invested in having."
Moreover, while uterine rupture is a clear risk of VBAC, there is growing recognition that women who have repeated caesareans have an increased risk for placenta-related complications. These can lead to dangerous maternal bleeding, pre-term birth and other adverse effects, and the risks increase steeply with each subsequent caesarean.
"There has been too much focus on the short-term risk of VBAC rather than looking at both the short-term and long-term risks," said Debra Bingham, president-elect of Lamaze International. "There is now much more evidence on the long-term risks for women who undergo repeated caesarean sections."
Because of the risk of uterine rupture, the American College of Obstetricians and Gynecologists in 1999 urged that VBAC should be offered only if a doctor was "immediately available" to provide emergency care. That policy is largely blamed for plummeting VBAC rates.
According to the panel's consensus statement, 30% of hospitals in two nationwide surveys said they stopped providing VBAC because they could not provide immediate surgical care.
The consensus statement urges professional physician groups to "reassess this requirement."
The obstetricians group is highly likely to do just that, said Dr. George A. Macones, a professor of obstetrics and gynecology at Washington University School of Medicine in St. Louis and a member of the group. "In a way, VBAC has been singled out" for this special requirement, he said.
"I think the fact that VBAC is not even an option for a lot of women is a shame," Macones said.