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

•Postpartum uterine contraction pain is common and severe in some women.•Multiparous women experience more intense postpartum uterine contraction pain.•Women with dysmenorrhea have a higher risk of postpartum uterine contraction pain.•Breastfeeding exacerbates uterine contraction pain in the early postpartum period.