#41 : The Effectiveness of GnRH Agonist Administration Prior to Frozen-Thawed Embryo Transfer with Artificial Cycle: A Systematic Review and Meta-Analysis of Different Protocols and Infertile Populations

Abstract

Background and Aims: We investigated the use of GnRHa pretreatment with different protocols and durations of treatment on pregnancy outcomes in women undergoing FET with artificial cycles (AC-FET). Method: A systematic search of PubMed, EMBASE, Google Scholar, and Cochrane library was performed to include only eligible peer-reviewed studies in English published before September 01, 2022. This review was registered on PROSPERO (CRD42022299259) Results: A total of 41 studies (43021 individuals) were included with low to moderate risk of bias. Overall, GnRHa pretreatment improved clinical pregnancy rate (CPR) (OR=1.27, 95%CI:1.12-1.44), implantation rate (IR) (OR=1.24, 95%CI:1.07-1.45), live birth rate (LBR) (OR=1.31, 95%CI:1.07-1.60) and endometrial thickness (MD=0.16, 95%CI:0.03-0.30). Subgroup analyses of randomized and non-randomized studies both demonstrated the benefits of GnRHa pretreatment in CPR, IR, and LBR. Protocols using depot GnRHa (OR=1.19, 95%CI:1.04-1.36) showed a better LBR than daily GnRHa (OR=1.04, 95%CI:0.93-1.16). Women administered GnRHa for more than one cycle had better CPR (OR=2.01, 95%CI:1.29-3.13) and IR (OR=2.14, 95%CI:0.98-4.67) than those treated with GnRHa within one cycle before FET ([OR=1.18, 95%CI:1.04-1.33] and [OR=1.16, 95%CI:1.01-1.32], respectively). In women with PCOS, pituitary suppression with GnRHa significantly improved CPR (OR=1.24, 95%CI:0.98-4.67), LBR (OR=1.22, 95%CI:1.05-1.42) and reduced the miscarriage rate (OR=0.75, 95%CI:0.59-0.95). In contrast, women with regular menstruation had a higher endometrial thickness (MD=0.16, 95%CI: 0.04-0.28) but no significant improvements in pregnancy outcomes. GnRHa pretreatment considerably improved IR (OR=2.21, 95%CI:1.60-3.07) in women with adenomyosis and CPR (OR=1.74, 95%CI:1.12-2.71), and LBR (OR=1.67, 95%CI:1.06-2.63) in women with endometriosis. Conclusion: GnRHa pretreatment, especially with longer suppression duration and the use of depot GnRHa, demonstrates a beneficial role during AC-FET cycles. Individuals with PCOS benefit from GnRHa pretreatment, though this FET protocol should be carefully considered in ovulatory women with regular menstruation. Albeit having the potential, effectiveness of this protocol on adenomyosis or endometriosis remains controversial and requires more rigorous investigation