Effect of GnRH agonist down-regulation combined with hormone replacement treatment on reproductive outcomes of frozen blastocyst transfer cycles in women of different ages

Objective . To investigate the effect of GnRH agonist (GnRH-a) down -regulation prior to hormone replacement treatment (HRT) to prepare the endometrium in frozen embryo transfer (FET) cycles in women of different ages. Methods . This was a retrospective study, and after excluding patients with adenomyosis, endometriosis, severe endometrial adhesions, polycystic ovary syndrome (PCOS), and repeated embryo implantation failures, a total of 4,091 HRT cycles were collected. Patients were divided into group A ( < 35 years old) and group B ( > 35 years old), and each group was further divided into HRT and GnRHa-HRT groups. The clinical outcomes were compared between groups. Results . There was no statistically significant difference in clinical outcomes between the HRT and GnRHa-HRT groups among women aged < 35 years. In women of advanced age, higher rates of clinical pregnancy and live birth were seen in the GnRHa-HRT group. Logistic regression analysis showed that female age and number of embryos transferred influenced the live birth rate in FET cycles, and in women aged > 35 years, the use of GnRH-a down -regulation prior to HRT improved pregnancy outcomes. Conclusions . In elderly woman without adenomyosis, endometriosis, PCOS, severe uterine adhesions, and RIF, hormone replacement treatment with GnRH agonist for pituitary suppression can improve the live birth rate of FET cycles.