Vaginal Delievery After C-section Mostly Safe
But Women Considering Vaginal Birth Should Know Individual Risks
Feb. 5, 2004 -- Women who have had a C-section but want to try a vaginal delivery the next time around may be relieved by the results of one of the most comprehensive studies ever to examine the practice. Almost three-quarters of the women in the study who attempted vaginal birth after C-section (VBAC) succeeded, and their complication rate was lower than women who had planned surgical deliveries.
Researchers estimated the risk for serious newborn complications to be one in 2000 deliveries when vaginal birth after C-section was attempted. Uterine rupture is the biggest concern with VBAC, but the complication occurred in less than 1% of women who took part in the study.
Ohio State University researcher and ob-gyn Mark Landon, MD, presented the findings in New Orleans Thursday at the annual meeting of the Society for Maternal-Fetal Medicine. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network funded the study.
Vaginal delivery was almost unheard of among women who had undergone C-sections prior to the 1970s. By the late 1990s almost one in three women in the U.S. who had had earlier C-sections attempted labor with their next pregnancy, but today the figure is closer to one in 10.
Why the big decline? Landon tells WebMD that many smaller hospitals stopped offering VBAC deliveries once they were required to have specially-trained physicians and anesthesiologists available in case of emergency. The fear of being sued has also made many ob-gyns think twice about recommending vaginal deliveries to women who have had C-sections.
Landon says it now seems clear that too many vaginal births following C-section were attempted prior to the decline, with rates at some hospitals exceeding 60% in the 1980s.
"Certain managed care organizations were pushing VBAC, claiming that it was a quality of care issue aimed at reducing cesareans when in fact it was an economic issue for many of them," he says. "In our study the VBAC rate was approximately 34%, which is much more realistic."
Most Babies OK After Rupture
The study involved women with a history of C-section giving birth at 19 medical centers across the country between 1999 and 2002. Of the 46,000 women with prior C-section deliveries, 18,000 attempted vaginal deliveries, 12,000 were advised to have another C-section for medical reasons, and 16,000 elected to have the surgery.
Of the 39% of women who attempted VBAC, 73% were successful. Women who had prior C-sections because of a breech birth or fetal distress had roughly an 80% chance of having a successful vaginal delivery.
The rates of uterine rupture among women attempting vaginal birth were less than 1%. Landon notes that of the 115 full-term deliveries ending in uterine rupture, two resulted in infant deaths and six others in infant brain injury.
"The chance of having an adverse outcome in the event of uterine rupture was about 7%," he tells WebMD. "This is certainly not insignificant, but the vast majority of babies delivered following uterine rupture survived intact."
Duke University professor of obstetrics and gynecology Haywood Brown, MD, says the findings should encourage women who want to try vaginal birth following a C-section delivery. But he explains that those who don't should not feel coerced to do so. Brown is immediate past president of the Society for Maternal-Fetal Medicine.
"The most important thing is for a woman and her doctor to consider her individual risks to determine if VBAC is an appropriate option," he tells WebMD. "