Introduction:Ovarian hyperstimulation syndrome (OHSS) is a common complication during assisted conception treatment, mostly seen in patients with ovarian hyperresponsiveness such as polycystic ovary syndrome, especially in post-invitro fertilization and embryo transfer (IVF-ET) pregnancies. Its main symptoms are abdominal distension, abdominal pain, nausea and vomiting with ascites, pleural fluid, leukocytosis, hemoconcentration and hypercoagulation. This disease is a self-limiting disease and can be gradually cured by rehydration, albumin infusion and correction of electrolyte disorders in moderate to severe cases. Luteal rupture is a more common gynecological emergency abdomen. The combination of twin pregnancy, OHSS and ruptured corpus luteum is very rare. We successfully avoided the stimulation of the risk of pregnancy abortion by surgical exploration through dynamic ultrasound monitoring and vital signs observation in the absence of experience in primary care, and the patient hard-won twin pregnancy was successfully treated conservatively.Patient concerns:The patient is a 30-year-old post-IVF-ET woman with an established twin pregnancy, OHSS and sudden onset of lower abdominal pain.Diagnosis:Twin pregnancy, OHSS combined with ruptured corpus luteum.Interventions:Rehydration, albumin infusion, low molecular heparin for thromboprophylaxis, luteinizing support, ambulatory ultrasound monitoring.Outcomes:After more than 10 days of standardized treatment for OHSS, dynamic ultrasound monitoring and close observation of vital signs, the patient was discharged cured of her condition and is continuing her pregnancy.Conclusion:Our case shows that the possibility of acute abdominal rupture of the corpus luteum is still present in the case of combined OHSS in pregnancy, and that some patients with corpus luteum rupture can heal spontaneously during close testing to avoid the increased risk of miscarriage with surgical exploration.