Comparison of pregnancy outcomes in women with normal ovarian response to the gonadotropin-releasing hormone agonist protocol using different trigger methods: a single-center retrospective cohort study based on propensity score matching

To investigate whether gonadotropin-releasing hormone agonist (GnRH-a) combined with human chorionic gonadotropin (HCG) can improve pregnancy outcomes in patients with normal ovarian response (NOR). In this retrospective cohort study, data of 404 NOR patients undergoing fresh embryo transfer (ET) from 2018 to 2022 were studied. Patients were divided into HCG group and HCG plus GnRH-a group according to trigger methods. After confounding factors were controlled by propensity score matching, 67 cases were included in HCG group and HCG plus GnRH-a group, respectively, and pregnancy outcomes were assessed. Basal data, ovarian stimulation, embryological data and pregnancy outcomes were compared. The effect of trigger methods on pregnancy outcomes was analyzed by binary logistic regression. There was no statistically significant differences in embryological data, embryo implantation rate, clinical pregnancy rate, live birth rate of ET, number of fresh embryos transferred and total number of embryos transferred after one cycle of oocyte retrieval. While, cumulative live birth rate (CLBR) was better in the dual-trigger group than in the HCG group. The binary logistic regression analysis indicated that the trigger methods had an independent influence on embryo implantation and cumulative live birth. During IVF/ICSI, dual-trigger could potentially play a role in improving oocyte quality, ensuring embryo implantation rate, clinical pregnancy rate, live birth rate of ET and cumulative live birth rate at the end of one ovum pick-up (OPU) cycle, and reducing the physical, temporal and financial negative consequences due to repeated OPU cycle.