Trends and Characteristics of Postpartum Hemorrhage in the Context of Declining Birth Rates: A Comparative Analysis of Cesarean and Vaginal Deliveries

Abstract Background Despite the decline in delivery volume, the incidence of postpartum hemorrhage (PPH) has shown an increasing trend. At our institution, the occurrence of PPH following vaginal delivery is higher than that after cesarean section. The primary objective of this study is to objectively assess this observation through data analysis, minimizing subjective assumptions. The secondary objective is to project future trends in PPH incidence at our center.Methods A retrospective cohort analysis was conducted using data from 1,790 deliveries (762 vaginal, 1,028 cesarean) at The First Affiliated Hospital of Naval Medical University (2021–2023). Obstetricians and midwives collaboratively assess blood loss, with PPH defined as ≥ 500 mL for vaginal deliveries or ≥ 1,000 mL for cesarean deliveries.Statistical analyses included t-tests, chi-square tests, Cochran-Armitage trend analysis, and Spearman’s correlation.Results The incidence of PPH was significantly higher in vaginal deliveries (15.1% vs. 2.1%, P < 0.001), with a greater median blood loss (320 mL vs. 300 mL, P < 0.001). A rising trend in PPH was observed from 2014 to 2024 (P < 0.001), which was inversely correlated with annual delivery volume (r= -0.918, P < 0.001).Conclusion Women undergoing vaginal delivery are at a higher risk of postpartum hemorrhage (PPH), which necessitates enhanced management of the obstetric delivery room and refined midwifery and obstetric techniques. The decline in delivery volume does not equate to a reduction in PPH cases; on the contrary, it presents greater clinical challenges.