Identifying the effect of inherited bleeding disorders on the development of postpartum hemorrhage: a population-based, retrospective cohort study.

BACKGROUND

Women with inherited bleeding disorders (IBDs) are at an increased risk of postpartum hemorrhage (PPH). However, the impact of other maternal predelivery risk factors, including anemia, on the association between IBD and maternal bleeding remains poorly understood. Additionally, studies examining potential pathways linking IBD and PPH are limited.

OBJECTIVES

We aimed to determine the risk of PPH associated with IBD.

METHODS

A retrospective cohort study was conducted using data held within ICES (formerly the Institute for Clinical Evaluative Sciences). Women with an in-hospital, live, or stillborn delivery between January 2014 and December 2019 were included. Poisson regression with robust error variance was used to determine the risk (RR) and 95% CIs of PPH among women with or without an IBD diagnosis. Models were stratified for primiparous and multiparous women.

RESULTS

Among the total population of 601,773 women, 29,661 (4.93%) experienced PPH. Multivariate models demonstrated that IBD was an independent risk factor for PPH among both the total cohort (adjusted RR [aRR] = 1.26; 95% CI: 1.08, 1.46) and primiparous women (aRR = 1.36; 95% CI: 1.12, 1.66). Among multiparous women, prior PPH was associated with an increased risk of PPH (aRR = 8.65; 95% CI: 8.32, 8.99), whereas IBD had no effect (aRR = 1.1; 95% CI: 0.86, 1.4). Predelivery anemia, placental conditions, multifetal gestation, and induction of labor were associated with increased PPH risk among all cohorts.

CONCLUSIONS

IBD significantly increases the risk of PPH. The management of delivery should be based on individualized assessment of risk factors to ensure optimal maternal outcomes.