Spontaneous conception and intrauterine pregnancy in a symptomatic missed abortion of ectopic pregnancy conceived in the previous cycle

We encountered a rare case of combined intrauterine and extrauterinepregnancy that occurred following separate spontaneous ovulations.A 33 year old woman visited our hospital with the chief complaintof abdominal pain on April 16, 1993. Her last menstruation wasfrom March 23 for 6 days. However, the urinary human chorionicgonadotrophin (HCG) on April 19 was 1024 IU/L Pelvic examinationand ultrasonography indicated an extrauterine pregnancy, whichwas confirmed by laparotomy and histo-logical identificationof trophoblast cells. The urinary HCG concentration markedlydecreased after the operation. However, the HCG level increasedagain on the fifth postoperative day, and a gestational sac(11 mm) was identified in the uterine cavity on the 11th post-operativeday, indicating that this intrauterine pregnancy was establishedfollowing spontaneous ovulation which occurred before the removalof the extrauterine pregnancy. This case indicates that a combinedpregnancy can occur not only after simultaneous multiple ovulationsbut also after the separate spontaneous ovulations.