Prostaglandin therapy during the proliferative phase improves pregnancy rates following frozen embryo transfer in a hormone replacement cycle

Aim To determine the efficacy of prostaglandin administration during the proliferative phase in order to improve pregnancy rates following frozen embryo transfer during a hormone replacement cycle (HRC). Methods From September 2010 through March 2012, patients (n = 135) were recruited who had undergone oocyte retrieval during a stimulation cycle with clomiphene and had deferred fresh embryo transfer (ET) due to a thin uterine endometrium. All patients were less than 40 years of age and underwent thawed ET following all embryo cryopreservation, and were randomly divided into two groups for thawed ET using a conventional hormone replacement cycle with or without prostaglandin derivatives (prostaglandin or conventional group). Prostaglandin derivatives were administrated during the proliferative phase. Pregnancy and implantation rates following frozen ET were compared between the two groups. Results Although the endometrial thickness on the day of ET was similar for the prostaglandin and conventional groups, the pregnancy and implantation rates for the prostaglandin group were 40.0% and 22.0%, respectively, which was significantly higher than the rates for the conventional group (P < 0.01). Conclusion Among patients who avoided fresh ET due to a thin endometrium, the pregnancy rate following a thawed cycle was low. However, it was improved when prostaglandin derivatives were used during the proliferative phase.