Clinical outcomes of personalized frozen-thawed embryo transfer timing for patients with recurrent implantation failure.

BackgroundRecurrent implantation failure (RIF) is a critical problem for assisted reproduction technology. High-quality embryos and the synchronization endometrium both have great significance. How to get the optimal endometrial receptivity is a challenge for implantation and pregnancy of infertile patients with RIF. The objective of this study is to investigate personalized protocol of frozen-thawed embryo transfer (FET) cycles, and its effect on clinical outcomes in patients with RIF.MethodsWe chose 91 RIF patients from January 2017 to June 2019 in the Reproductive Medicine Center of the First Hospital of Lanzhou University. A total of 100 FET cycles were undertaken with a gonadotropin-releasing hormone agonist (GnRH-agonist) protocol combined with hormone replacement therapy (HRT) for endometrial preparation. The patients were divided into two groups: the routine group (cleavage embryo transferred at day 3 after luteal support) included 48 cycles; the personalized group included 52 cycles with delayed endometrial trigger and luteal support (the time of embryo transfer depended on the level of serum hormone and endometrial thickness).ResultsThe data showed the personalized group had longer time for endometrial preparation. On the day of embryo transfer, serum progesterone (P) and the E2/P ratio was significantly different compared with the routine group (P<0.05). The clinical pregnancy rate in the routine group was 35.42% (17/48) and 59.62% (31/52) in the personalized group (P<0.05). The abortion rate was not significantly different.ConclusionsFor women with RIF, personalized timing for transfer of FET resulted in a higher clinical pregnancy rate compared with routine protocol.