Racial variation in the frequency of intrapartum hemorrhage

To evaluate racial variation in the frequency of intrapartum hemorrhage.

Using information from birth certificates of live singleton births in North Carolina from 1990 to 1997 (n = 807,759), we evaluated the frequency of intrapartum hemorrhage and its association with maternal race. Logistic regression models were used to evaluate the risk of any intrapartum hemorrhage, placental abruption, placenta previa, and unspecified hemorrhage in each racial group, adjusted for other risk factors.

Black women had the highest rates of any hemorrhage (1.52% black, 1.47% white, 1.33% other race, P =.006) and placental abruption (0.79% black, 0.68% white, 0.56% other race, P =.001) but had lower rates of unspecified hemorrhage (0.37% black, 0.42% white, 0.42% other race, P =.001). Race was not associated with placenta previa. Maternal race remained associated with intrapartum hemorrhage after multivariable analysis, but the direction of the association was reversed. Black women were less likely to have any intrapartum hemorrhage (odds ratio [OR] 0.80, 95% confidence interval [CI] 0.77, 0.85), placental abruption (OR 0.76, 95% CI 0.70, 0.82), placenta previa (OR 0.89, 95% CI 0.81, 0.98), or other unspecified hemorrhage (OR 0.84, 95% CI 0.76, 0.92) compared with white women. Women of other minority races were at lower risk for placental abruption (OR 0.76, 95% CI 0.67, 0.87) but were comparable to white women for risk of placenta previa (OR 1.06, 95% CI 0.91, 1.24) and other unspecified hemorrhage (OR 1.02, 95% CI 0.88, 1.19).

Although black women had higher rates of intrapartum hemorrhage than whites, the increased frequency was attributable to differences in clinical presentation and other risk factors.