Family history of postpartum hemorrhage is a risk factor for postpartum hemorrhage after vaginal delivery: results from the French prospective multicenter Haemorrhages and Thromboembolic Venous Disease of the Postpartum cohort study

Abstract

Postpartum hemorrhage (PPH) is a major component of perinatal morbidity and mortality affecting young women worldwide, and is still often unpredictable. Reducing the incidence of PPH is a major health issue, and identifying women at risk for PPH is a key element in preventing this complication. To estimate PPH prevalence after vaginal delivery and to identify PPH risk factors. Unselected pregnant women ≥ 16 years attending one of six maternity wards in Brittany (France) for vaginal birth after 15 weeks of gestation were recruited in this prospective multicenter cohort study between June 1, 2015 and January 31, 2019. PPH was defined as a blood loss ≥ 500 mL in the 24 hours following delivery. Independent risk factors for PPH were determined by logistic regression. Missing data were compensated by multiple imputation (MICE method). Among 16,382 included women, PPH prevalence was 5.37%. A first-degree family history of PPH (aOR = 1.63, 95%CI 1.24-2.14) and a personal transfusion history (aOR = 1.90, 95%CI 1.23-2.92) were significantly associated with PPH. The use of oxytocin during labor was also a risk factor for PPH (aOR = 1.24, 95%CI 1.06-1.44). Inversely, smoking during pregnancy and intrauterine growth restriction were associated with a reduced risk of PPH (aOR = 0.76, 95%CI 0.63-0.91, and 0.34, 95%CI 0.13-0.87, respectively). In addition to classical risk factors, this study identified PPH family history and personal transfusion history as new characteristics associated with PPH after vaginal delivery. The association of PPH with a family history of PPH suggests a hereditary hemorrhagic phenotype and calls for genetic studies. Identifying women at risk for PPH is a key element in being prepared for this complication.