Factors Associated with Blood Loss after Delivery in 1,294 Mothers with Full-Term Singleton Baby

Objectives: To clarify the predisposing factors associated with blood loss after delivery in mothers with full-term singleton babies. Methods: In this retrospective cohort study, we investigated 1,294 women who delivered singleton babies vaginally in 2011 at a medical center in Tokyo. We determined the amount of blood loss after delivery and covariates of age, parity, pre pregnancy body mass index (BMI), gestational weight gain (GWG), gestational week, pregnancy complications, lifestyles of smoking and drinking, placental weight, and infant weight and sex. Results: The majority of participants had lost less than 500 ml of blood (n=868, 67%), 21% lost between 500–799 ml of blood (n=273), 12% lost 800 ml or more of blood (n=153). The amount of blood loss statistically increased (p