Incidence and Antepartum Risk Factors of Severe Postpartum Haemorrhage in Anaemic Pregnant Women in Lagos, Nigeria: A Secondary Cohort Analysis.

Abstract

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. The study determined the incidence and antepartum risk factors of severe PPH in anaemic pregnant women in five health institutions in Lagos, Southwest Nigeria. A secondary analysis was performed using the data of pregnant women with anaemia from the "Predict-PPH" study that was 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 an estimated blood loss of at least 1000 mL within 24 hours of childbirth. A backward stepwise conditional approach in a multivariable logistic regression model was utilised to identify the independent risk factors for severe PPH in anaemic pregnant women. Of the 570 women with prenatal anaemia enrolled in the primary study, 42 (7.4%) had severe PPH. The identified independent risk factors for severe PPH were maternal obesity (adjusted OR = 3.85, 95% CI = 1.85-8.02), antepartum haemorrhage in index pregnancy (adjusted OR = 2.98, 95% CI = 1.29-6.90), uterine fibroids (adjusted OR = 6.10, 95% CI = 2.39-15.52), delivery gestational age ≥39 weeks (adjusted OR = 2.62, 95% CI = 1.23-5.56), and delivery by caesarean birth (adjusted OR = 16.75, 95% CI = 5.81-48.31). About one in 13 anaemic pregnant women enrolled in the study developed severe PPH during childbirth. 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 findings underscore the importance of increased vigilance during both the antenatal and peripartum periods to identify women with these risk factors for the initiation of timely interventions to prevent severe PPH.