Hormone replacement therapy with GnRH agonist pretreatment improves pregnancy outcomes in patients with previous intrauterine adhesions

PURPOSETo explore the optimal cycle regimen for frozen-thawed embryo transfer (FET) in women with previous intrauterine adhesions (IUAs). METHODSIn this retrospective cohort study, a total of 1,002 FET cycles for patients with previous IUAs from January 2015 to December 2020 were included. Among them, 294 conventional hormone replacement therapy (HRT) cycles were matched with 155 HRT with gonadotropin releasing hormone agonist pretreatment (HRT+GnRH-a) cycles using propensity score matching. Multivariate logistic regression analysis was performed to further investigate the impact of cycle regimen on pregnancy outcomes. RESULTSAfter propensity score matching, baseline characteristics were consistent between HRT and HRT+GnRH-a group. Logistic regression analysis revealed that there was a significant superiority of HRT+GnRH-a over the conventional HRT group regarding the incidences of live birth (aOR=1.966, 95%CI: 1.212-3.188, P=0.006) and ongoing pregnancy (aOR=1.710, 95%CI: 1.057-2.767, P=0.029). HRT+GnRHa also had a higher odd of clinical pregnancy (aOR=1.414, 95%CI: 0.903-2.216, P=0.130), and lower odd of early miscarriage (aOR=0.511, 95%CI: 0.219-1.195, P=0.121) compared to HRT, yet not reached statistical significance. CONCLUSIONHRT with GnRH-a pretreatment improves pregnancy outcomes in women with previous IUAs. GnRH-a may restore the endometrial receptivity in the FET cycles of IUAs. SYNOPSISHRT with GnRH-a pretreatment may promote pregnancy prognosis of FET in women with history of IUAs by restoring endometrial receptivity.