Incidence, severity, and determinants of uterine contraction pain after vaginal delivery: a prospective observational study

Abstract Background Postpartum uterine contraction pain has not been studied sufficiently. We aimed to assess the incidence, intensity, and risk factors for postpartum uterine contraction pain. Methods Women with singleton pregnancies who delivered vaginally were enrolled in this prospective, observational, single-institution study. We determined the numerical rating scale (NRS) score (0 to 10-point) for uterine contraction pain at 6 h, 12 h, 24 h, and 48 h after delivery. Generalized mixed modeling was used to identify the risk factors for significant postpartum uterine contraction pain (NRS score ≥3). We compared the incidence and severity of postpartum uterine contraction pain between nulliparous and multiparous women. Results Two hundred sixty-five nulliparous and 139 multiparous women were included. Forty-seven percent (188/404; 95% confidence interval [CI] 41.7% to 51.4%) of women presented with significant uterine contraction pain within 48 h of delivery. The generalized mixed model showed that nulliparous women had a lower risk of significant postpartum uterine contraction pain compared with multiparous women (odds ratio [OR] 0.325, 95% CI 0.175 to 0.606; P Conclusions Postpartum uterine contraction pain is common and severe in some women. Parity and history of dysmenorrhea are significant risk factors for significant postpartum uterine contraction pain.