Spontaneous resolution of ectopic pregnancy in a surrogate after oocyte donation and frozen embryo transfer

A case of tubal pregnancy in a young and healthy woman participating in a programme of in-vitro fertilization (IVF) gestational surrogacy is reported. The gestational surrogate was the 30 year old fertile sister of a 25 year old patient affected by stage 1 ovarian cancer. After mandatory oncological consultation, the donor was recommended to prospectively undergo controlled ovarian hyperstimulation cycles for embryo banking before being treated by total hysterectomy. Available embryos were cryopreserved and after adequate endometrial preparation using artificial cycles of hormone replacement therapy, three thawed frozen embryos were transferred to the surrogate. At 17 days following embryo transfer the surrogate was noted to have a negative β-human chorionic gonadotrophin (HCG) serum concentration. All medication was suspended and a few days later normal menstrual bleeding occurred. After 2 weeks, the β-HCG concentrations, performed as part of routine follow-up evaluation, were showing signs of trophoblast activity (236 mIU/ml). Taking into account the stable condition of the patient, a decision was made to undertake expectant management. At 43 days after embryo transfer, a complete tubal abortion was apparently seen in the posterior cul-de-sac by ultrasound associated with a subtle and short lasting pelvic pain. We stress that this ectopic gestation was able to maintain prolonged viability in conditions of absent corpus luteum and exogenous steroid supplementation.