Association Between Third‐Stage Duration and Postpartum Hemorrhage in Women With Retained Placenta

Aim To examine the association between third‐stage duration and total blood loss in women with retained placenta. Secondary analyses were performed to explore clinical factors associated with postpartum hemorrhage (PPH). Methods This retrospective cohort study included women with singleton vaginal deliveries at ≥ 22 gestational weeks between 2019 and 2024 complicated by retained placenta. The association between third‐stage duration and total blood loss was assessed using Spearman's correlation. Multivariable logistic regression analysis was used to explore factors associated with PPH. Blood loss and third‐stage duration were descriptively compared between cases with and without manual removal of the placenta (MROP). Results Among 4543 vaginal deliveries, 47 (1.0%) cases of retained placenta were identified, of which 27 (57.4%) developed PPH. Total blood loss positively correlated with third‐stage duration (Spearman's ρ = 0.488, p < 0.001). In exploratory multivariable analysis, assisted reproductive technology (ART) pregnancy (adjusted odds ratio [aOR], 18.50; 95% confidence interval [CI], 3.28–104.0) and third‐stage duration (per 30 min: aOR, 1.86; 95% CI, 1.10–3.16) were associated with PPH, although the estimates were imprecise. MROP was performed in 32 patients (68.1%) at physician discretion. Third‐stage duration did not differ between groups, but greater blood loss was observed in cases in which MROP was performed. Conclusion Prolonged third‐stage duration was associated with greater blood loss in women with retained placenta and may reflect the overall clinical course rather than an isolated causal factor. ART pregnancy was also associated with PPH.