Maternal Mortality and Analgesia: The Unseen Connection of Epidurals and Postpartum Hemorrhage, study finds

Postpartum hemorrhage (PPH) remains the leading cause of maternal mortality globally, particularly affecting women with gestational hypertension due to their vulnerability to blood volume reduction. A recent retrospective cohort study analyzed the impact of epidural labor analgesia on blood loss within two hours post-delivery in this specific population, a critical period where up to 80% of total blood loss can occur.

Study Population and Methodology

The study included 1,903 participants who met the diagnostic criteria for gestational hypertension and were candidates for vaginal delivery. Data were meticulously collected from electronic medical records spanning nearly a decade. Comprehensive statistical analyses were performed using SPSS and R, encompassing both bivariate and multivariate logistic regression to explore associations with postpartum hemorrhage defined as blood loss of ≥300 mL. Results highlighted a prevalence of 16.9% of participants experiencing PPH of ≥300 mL. Multivariate logistic regression identified epidural analgesia as an independent risk factor for early postpartum hemorrhage (adjusted odds ratio (OR) = 1.30, 95% CI: 1.01–1.68, P = 0.039), alongside macrosomia and placental adhesion. In contrast, birth canal injury appeared protective against PPH. Notably, traditional risk factors such as age, BMI, and oxytocin use did not demonstrate significant associations with early blood loss. Prior studies have suggested that epidural analgesia does not increase PPH risk in non-hypertensive populations, raising questions about the unique pathophysiology associated with gestational hypertension. The mechanisms proposed include uteroplacental perfusion dysregulation due to vasospasm, which may impair uterine contractility, and potential disruptions to the vascular-coagulation pathway enhancing bleeding risk. Furthermore, the analysis reinforced previous findings where high BMI correlates with increased PPH risk. Critically, the definition of a ≥300 mL postpartum hemorrhage threshold was employed based on prior studies indicating its clinical relevance for early identification of PPH risk. However, the exclusive focus on the first two hours postpartum may overlook significant later blood loss, necessitating ongoing monitoring up to 24 hours.

Conclusions and Future Directions

The study concludes by calling for further prospective investigations to validate these findings and to optimize analgesic protocols to balance pain management with hemorrhagic risk in women with gestational hypertension, aiming to enhance maternal safety during childbirth.

Key Points

- Postpartum hemorrhage (PPH) is identified as the leading cause of maternal mortality worldwide, with heightened risk in women experiencing gestational hypertension due to susceptibility to substantial blood volume loss.

- A retrospective cohort study involving 1,903 women with gestational hypertension assessed the effect of epidural labor analgesia on blood loss within the first two hours post-delivery, a critical period for PPH occurrence. - Results showed a 16.9% prevalence of postpartum hemorrhage ≥300 mL, with multivariate logistic regression revealing that epidural analgesia (adjusted OR = 1.30, 95% CI: 1.01–1.68, P = 0.039), macrosomia, and placental adhesion were significant independent risk factors, while birth canal injury was protective.

- The investigation contradicted prior findings in non-hypertensive populations where epidural analgesia did not correlate with increased bleeding risk, suggesting a unique pathophysiological response in gestational hypertension that could affect uterine contractility and promote bleeding.

- The analysis reaffirmed that higher body mass index (BMI) is associated with increased PPH risk, accentuating the importance of considering obesity as a critical factor in monitoring bleeding risk during and after delivery.

- Recommendations emphasize the need for prospective studies to confirm these results and to refine analgesic strategies that effectively manage pain while minimizing hemorrhagic complications in patients with gestational hypertension, thereby improving maternal safety during labor.

Reference –

Weiguo Sun et al. (2025). Epidural Labor Analgesia Is A Potential Risk Factor For Increased Blood Loss Within Two Hours After Delivery In Women With Gestational Hypertension: A Retrospective Cohort Study. *BMC Pregnancy And Childbirth*, 25. https://doi.org/10.1186/s12884-025-07648-3.