The addition of single dose GnRH agonist to luteal phase support in artificial cycle frozen embryo transfer: a randomized clinical trial

This prospective randomized clinical trial (RCT) was to evaluate the effect of single-dose gonadotrophin-releasing hormone agonist (GnRHa) in artificial cycle frozen-embryo transfer (AC-FET). A total of 868 FET cycles were included and randomized into two groups: Group A (n?=?434) received GnRHa 0.1?mg subcutaneous injection on day 3 after embryo transfer (ET); Group B (n?=?434) did not receive GnRHa. The demographic characteristics, primary endpoint (implantation rate) and secondary endpoints (chemical pregnancy rate, clinical pregnancy rate, ongoing pregnancy rate) were compared between two groups and subgroups (aged <35?years and 35-37?years). There were no significant differences in terms of the rates of implantation, clinical pregnancy, ongoing pregnancy, and miscarriage between two groups. While, the subgroups analysis showed the implantation rate was significantly increased in advanced age women (35–37?years) in GnRHa group compared with control group (45.3% vs. 27.8%, p?=?.03). In conclusion, single dose of GnRHa (0.1?mg triptorelin acetate) supplementation 3?days after ET in AC-FET cycles did not show significant benefit on pregnancy outcomes as a whole. However, in ageing women subgroup, the implantation rate was increasing by adding up GnRHa in peri-implantation periods, and this tendency needs to be further demonstrated by RCT with larger sample size.