Optimal Parity Cut-off Values for Predicting Postpartum Hemorrhage in Vaginal Deliveries and Cesarean Sections

Background: High parity is a major public health concern in developing countries and it is a risk factor for postpartum hemorrhage (PPH). The aim of this study was to analyze the optimal parity cut-off values for predicting PPH in vaginal deliveries and cesarean sections in a rural Zambian setting. Methods: All women who delivered at Zimba Mission Hospital in 2017 were reviewed in this retrospective survey. Those whose records were missing data on parity and those with risk factors for developing PPH (e.g. birth weight ≥ 4,000 g, multiple pregnancy, assisted vaginal delivery, and placenta previa) were excluded. We analyzed the association between parity and PPH using multiple logistic regression and ROC curve analyses. Results: Among the 1,555 women included in the study, 72 (4.6%) women experienced PPH. The optimal cut-off values for parity in vaginal deliveries and cesarean sections were para 7 and 3, respectively. Using these cut-off values, the adjusted odds ratios (95% confidence intervals) were 3.26 (1.15, 9.21) and 8.28 (2.25, 30.5), respectively. Conclusions: Proper preparation is required for vaginal deliveries in women with a history of ≥ 7 births and cesarean sections in women with a history of ≥ 3 births.