A cohort analysis of incidence and antepartum risk factors of severe postpartum haemorrhage in anaemic pregnant women in Lagos, Nigeria

Abstract

Abstract Background:The magnitude and risk factors for postpartum haemorrhage (PPH) have been extensively investigated, although little is currently known about the incidence and predictors of severe PPH, specifically among women affected by prenatal anaemia in Nigeria. Objectives: We determined the incidence and antepartum risk factors of severe PPH in anaemic pregnant women in five health institutions in Lagos, Southwest Nigeria. Methods: We performed a secondary analysis of the data of pregnant women with anaemia from the "Predict-PPH" study conducted between January and June 2023. This study included n=570 pregnant women affected by anaemia who gave birth in five hospitals in the Lagos metropolis of Nigeria. The study outcome was severe PPH, defined as estimated blood loss of at least 1000 mL within 24 hours of childbirth. We utilized a backward stepwise conditional approach in a multivariable logistic regression model to highlight the independent risk factors associated with severe PPH. Results: Of the 570 women with prenatal anaemia enrolled in the primary study, 42 (7·4%) had severe PPH. The identified independent risk factors of severe PPH were maternal obesity (adjusted odds ratio=3.85, 95% confidence interval: 1.85–8.02), antepartum haemorrhage in index pregnancy (adjusted odds ratio=2.98, 95% confidence interval: 1.29–6.90), uterine fibroids (adjusted odds ratio=6.10, 95% confidence interval: 2.39–15.52), delivery gestational age ≥39 weeks (adjusted odds ratio=2.62, 95% confidence interval: 1.23–5.56) and delivery by caesarean birth (adjusted odds ratio=16.75, 95% confidence interval: 5.81–48.31). Conclusion: Compared to the general women population, we reported a relatively higher incidence of severe PPH in anaemic pregnant women. Maternal obesity, antepartum bleeding in the current pregnancy, co-existing uterine fibroids in pregnancy, delivery gestational age beyond 38 weeks, and caesarean birth in the current pregnancy were factors that were significantly associated with severe PPH in anaemic pregnant women. These underscore the importance of heightened vigilance during both the antenatal and peripartum periods to identify women with these risk factors for initiation of timely interventions to prevent severe PPH.