Effect of GnRH-a pretreatment before frozen-thawed embryo transfer on pregnancy outcome of adenomyosis-associated infertile patients with 56 cm(3) ≤ uterine volume ≤100 cm(3)

BACKGROUND: Whether gonadotrophin-releasing hormone agonist (GnRH-a) pretreatment before transferring frozen-thawed embryos (FETs) could improve the clinical outcome of adenomyosis-associated infertile patients with 56 cm(3) ≤ uterine volume ≤100 cm(3) is unclear. METHODS: Adenomyosis patients who underwent in vitro fertilization and frozen embryo transfers from January 2009 to December 2019 with 56 cm(3) ≤ uterine volume ≤100 cm(3) were included in this retrospective cohort study. The subjects were divided into two groups (GnRH-a treatment group vs. GnRH-a-free group). The effect of GnRH-a treatment before FET on pregnancy outcomes was explored by univariate and multivariate analysis. In the GnRH-a treatment group, uterine volume before and after GnRH-a pretreatment was also compared by t-tests. RESULTS: A total of 186 patients undergoing 263 cryopreserved embryo transfer cycles were included. There was no significant difference in terms of the clinical pregnancy rate between patients in the GnRH-a treatment group (24/45, 53.3%) and the GnRH-a-free group (86/218, 39.4%) (P=0.098). The miscarriage rate in the GnRH-a treatment group (3/24, 12.5%) was significantly lower than that in the GnRH-a-free group (32/86, 37.2%) (P=0.044). The live birth rate in the GnRH-a treatment group (21/45, 46.7%) was significantly higher than that in the GnRH-a-free group (54/218, 24.8%) (P=0.009). However, the uterine volume did not change significantly before (82.0±13.4 cm(3)) or after GnRH-a treatment (79.3±14.0 cm(3)), with a P=0.123. CONCLUSIONS: GnRH-a pretreatment before FET reduced the miscarriage rate and improved the live birth rate among infertile women with adenomyosis whose uterine volume was 56–100 cm(3).