Effects of artificial cycles with and without gonadotropin-releasing hormone agonist pretreatment on frozen embryo transfer outcomes

OBJECTIVE: This study aimed to compare the pregnancy outcomes between women receiving frozen embryo transfer (FET) with hormone replacement treatment (HRT) with and without gonadotropin-releasing hormone agonist (GnRHa) pretreatment. METHODS: All consecutive women undergoing HRT cycles (2936 cycles) or HRT with GnRHa pretreatment (HRT + GnRHa, 303 cycles) at our reproductive center between January 2015 and December 2017 were analyzed retrospectively. RESULTS: The average age was higher in the HRT + GnRHa compared with the HRT group (34.0 ± 4.8 vs. 31.3 ± 4.4). However, the pregnancy outcomes were comparable between the two groups. The clinical pregnancy rate was significantly increased in younger women (≤35 years) in the HRT + GnRHa group compared with the HRT group (56.8% vs. 48.7%), but the live birth rates were similar in the two groups (44.2% vs. 38.4%). The HRT + GnRHa protocol significantly increased the clinical pregnancy rate (55.6% vs. 43.2%) and live birth rate (43.5% vs. 33.5%) compared with the HRT group among women with endometriosis, and significantly decreased the abortion rate in women with polycystic ovarian syndrome (3.1% vs. 16.4%). CONCLUSIONS: GnRHa pretreatment may improve pregnancy outcomes in women with endometriosis and polycystic ovarian syndrome.