Body mass index and severe postpartum hemorrhage.

Background/aims: The purpose of this study was to determine the relationship between maternal characteristics and severe postpartum hemorrhage (PPH).

Methods: Medical records of women who delivered at Duke University Hospital between 2001 and 2004 with an ICD-9 code for PPH were reviewed. Women with PPH who received blood component therapy (severe PPH) were selected as cases and compared with controls matched for age, parity and mode of delivery.

Results: Among 12,476 deliveries, there were 109 women with severe PPH. Hispanic women had an almost fourfold increase in the odds of severe PPH [OR 3.9 (1.8, 8.7)] that persisted when controlling for other significant predictors of PPH. Women with PPH were almost two times more likely [OR 1.8 (1.1, 3.1)] to have a BMI <30 when controlling for Hispanic ethnicity, oxytocin exposure, labor induction, treatment with magnesium and chorioamnionitis.

Conclusion: Systemic factors as well as obstetrical factors modify the risk of severe PPH. Hispanic women and women with a BMI <30 are more likely to have severe PPH. When mode of delivery is controlled for, BMI ≥30 is associated with a reduced risk of severe PPH.