Objective: The aim of this study was to analyse the surgical and conservative management of RPOC after 34 weeks of gestation and to elucidate its natural course. Design: Retrospective cohort study Setting: Study in a single center Population: Patients diagnosed RPOC at Kindai university from January 2013 to March 2022 Methods: Clinical data from patients’ electronic medical records was reviewed retrospectively. Main outcome measures: The onset of heavy bleeding, date of RPOC disappearance, and serial changes of serum hCG. Results: 19 of 41 cases of RPOC diagnosed after 34 weeks of gestation had the retained placenta manually removed within 24 hours of delivery; nine cases had no emergent symptoms before placental removal; and five and three cases experienced heavy bleeding during and after placental removal, respectively. Six out of 22 cases with RPOC managed conservatively had heavy bleeding for no determinable reason. Six cases experienced heavy bleeding during the placental extraction trial. These events occurred within 60 days of delivery. RPOC disappeared spontaneously in 17 cases (77%), with a median time of 130 days. Serum human chorionic gonadotropin of the 14 patients who did not undergo UAE, fell below the measurable threshold at a median of 67 days postpartum, with a half-life of 4.7 days. Conclusion: RPOC in late pregnancy can cause heavy bleeding and infection, but these events do not occur after 60 days postpartum, and spontaneous resolution of RPOC is possible. Conservative management may be an option in the treatment protocols for RPOC.