Does Depot Analog Suppression Have Positive Effects on All Other Frozen-thawed Embryo Transfer Cycles in Addition to Endometriosis?

Abstract

Introduction: The study investigated whether Gonadotropin-releasing hormone analog (GnRH-a) suppression before elective frozen-thawed embryo transfer (FET) allows better ongoing pregnancy rates (OPR) in women without endometriosis. Material and methods: Retrospective cohort study including FET cycles performed in one academic fertility center from 2014 October to 2019 December. In the analog suppression group (ASG), depot analog was given on day 2 or 3, and estradiol (E2) treatment was started on the 21st day of analog usage. Intramuscular progesterone (100 mg/d) was added to E2 till the fetal heartbeat was seen. Then vaginal progesterone (600 mg/d) was continued until the 12th week of gestation. Results: Among 523 FET, 22.4% underwent analog suppression, 77.6% had not undergone analog suppression before FET. There was no difference between groups concerning endometrial thickness, the number of embryos transferred, development of embryo stage at FET cycle, and cryopreservation technique. Implantation rate and ongoing pregnancy rates were significantly higher in the ASG than in the non-analog suppression group (NASG). Conclusion: The use of GnRH-a before FET increases implantation rate and ongoing pregnancy rate not only in endometriosis cases but also in other patients with different infertility causes.