From Reuters Health Information
NEW YORK (Reuters Health) Feb 29 - Black women who attempt vaginal birth after cesarean delivery (VBAC) are significantly less likely to experience a uterine rupture than women of other races, findings from a large cohort study indicate.
In the March issue of Obstetrics and Gynecology, Dr. Alison G. Cahill and colleagues at the Washington University in St. Louis caution that the risks of attempting VBAC "differ dramatically by race, and a one-size-fits-all approach to planning delivery modality in patients with a history of a prior cesarean should be re-evaluated."
Until now, the effect of maternal race on the likelihood of VBAC success and the risk for associated morbidities has not been well characterized, the investigators note.
Using data from a retrospective cohort study conducted in the northeastern US from 1995 to 2000, Dr. Cahill's team identified 13,706 patients with a history of at least one prior cesarean delivery who elected to attempt VBAC.
Their initial analyses of patients' medical records showed that Asian and Hispanic women were similar to white women with respect to risk factors and outcomes.
Black women were more likely than women of other races to attempt VBAC (62% vs 52%) and were more likely to have a failed VBAC trial (26% vs 24%), according to the researchers. Black women, however, were 40% less likely to experience a uterine rupture (adjusted odds ratio 0.6, p = .01).
The reduced risk of uterine rupture associated with black race was also observed in the subset of patients who had failed their VBAC attempt (adjusted odds ratio 0.4, p < .01).
The authors suggest that well documented ethnic differences in pelvic connective tissue may underlie their findings.
"Knowing that the rates of VBAC-associated morbidities, such as uterine rupture, vary greatly by race, it may be appropriate to consider more patient-specific risk-benefit counseling," Dr. Cahill and her associates conclude.