Definition of prolonged third-stage labor may be outdated

(HealthDay)—Postpartum hemorrhage risk is significantly elevated with a third-stage labor duration of 20 minutes or more, according to research published in the May issue of Obstetrics & Gynecology.

Antonina I. Frolova, M.D., Ph.D., from the Washington University School of Medicine in St. Louis, and colleagues performed a secondary analysis of a cohort of 7,121 women who had a vaginal delivery at or beyond 37 weeks 0 days of gestation. The authors estimated the correlation between increased duration of third stage of labor and incidence of postpartum hemorrhage.

The researchers found that among women who had a vaginal delivery, the mean duration of the third stage of labor was 5.46 minutes and median duration 4 minutes. For the 705 women with a third stage above the 90th percentile (nine minutes), the risk of postpartum hemorrhage was increased compared with a third stage below the 90th percentile (13.2 versus 8.3 percent; adjusted odds ratio, 1.82). The risk for postpartum hemorrhage increased significantly beginning at 20 to 24 minutes, compared with shorter duration of the third stage (15.9 versus 8.5 percent; adjusted odds ratio, 2.38). There was no correlation for blood transfusion with third-stage duration.

"Our data show that postpartum hemorrhage risk increases significantly when the third stage of labor duration is 20 minutes or more, suggesting that the definition of a prolonged third stage of labor being 30 minutes or more may be outdated," the authors write.