ABSTRACT
Heterotopic pregnancy is an extremely rare condition in which an intrauterine and an extrauterine pregnancy co-exist. In spontaneous conceptions, heterotopic pregnancy occurs in only 1/30 000 pregnancies. The treatment of heterotopic pregnancy must be as minimally invasive as possible to preserve the development of the intrauterine pregnancy. Superfetation, defined as the coexistence of 2 or more foetuses of different gestational ages, remains particularly exceptional and poorly explained (second ovulation? embryonic diapause?). Here, we present an extremely rare case of a spontaneous heterotopic evolutive pregnancy with superfetation, consisting of an embryo in the pouch of Douglas estimated at 8 + 1 weeks of gestation (WG) and a progressive intrauterine pregnancy estimated at 5 + 4 WG. We treated the extrauterine pregnancy with an intra-cardiac injection of potassium chloride echo-guided via the vaginal route, and the patient then underwent exploratory laparoscopy 9 days later and lavage and aspiration of the abdominal heterotopic pregnancy due to pain and biological inflammatory syndrome probably caused by pelvic mass syndrome and peritoneal irritation from the foetal necrosis. She has not yet given birth and is currently at 36 WG.
