Erceg Ivkosic I, Dmitrovic R, Vujisic S, Bauman R, Hafner D and Habek D
Heterotopic Pregnancy (HP) is a very rare entity, but due to the use of In Vitro Fertilization (IVF) techniques
it is now a common complication of IVF. However, there are no literature reports of HP when a Frozen-Thawed Embryotransfer (FET) of blastocysts is performed. In stimulated cycles, one or two embryos are replaced usually on days 3-5 after follicular aspiration and the rest are frozen for future FET attempts. This adds much to the cumulative pregnancy rate for the particular cycle, especially if the frozen embryos are blastocysts. However, there are no reports of HP with FET of blastocysts, although HP with FET of 3 day embryos has been previously reported.
We report a case of a 35-year old patient, 7-weeks pregnant after the FET of two thawed blastocysts, who
presented into the emergency room in a state of a hemorrhagic shock, with no vaginal bleeding. At her previous exam, at 5+3 weeks of pregnancy, one gestational sac in the uterus was visualized. At admission, Transvaginal Ultrasound (TVU) revealed an adnexal mass on the right side of the lower abdomen, an abdominal cavity filled with large amount of free fluid, and a two-millimeter embryo with a positive heart rate in the uterus. An emergency laparotomy and right salpingectomy were performed, and HP was confirmed. The intrauterine pregnancy continued without any complications, and resulted in a vaginal delivery of a live-born child, at full term. Caution should be exerted when two cryopreserved and thawed blastocysts are transferred, because there is the possibility of a HP.