Effect of LH level on HCG trigger day on clinical outcomes in patients with diminished ovarian reserve undergoing GnRH-antagonist protocol.

Research Question: Does luteinizing hormone (LH) levels on human chorionic gonadotropin (HCG) trigger day (LH) affect the clinical outcomes of patients with diminished ovarian reserve (DOR) undergoing gonadotropin-releasing hormone antagonist (GnRH-ant) protocol?

Methods: Retrospective analysis fresh embryo transfer cycles of DOR patients who underwent GnRH-ant protocol from August 2019 to June 2023. The participants were divided into different groups according to LH level and age. The clinical data and outcomes were compared between groups.

Results: In patients with DOR, the HCG positive rate (59.3% versus 39.8%, P = 0.005), embryo implantation rate (34.5% versus 19.7%, P = 0.002), clinical pregnancy rate (49.2% versus 28.4%, P = 0.003), live birth rate (41.5% versus 22.7%, P = 0.005) in LH < 2.58 IU/L group were significantly higher than LH ≥ 2.58 IU/L group. There was no significant correlation between LH level and clinical pregnancy in POSEIDON group 3. In POSEIDON group 4, the HCG positive rate (52.8% versus 27.0%, P = 0.015), embryo implantation rate (29.2% versus 13.3%, P = 0.023), clinical pregnancy rate (45.3% versus 18.9%, P = 0.010) in LH < 3.14 IU/L group were significantly higher than LH ≥ 3.14 IU/L group. Logistic regression analysis indicated that LH level was an independent influencing factor for clinical pregnancy in POSEIDON group 4 patients (OR = 3.831, 95% CI: 1.379-10.643, P < 0.05).

Conclusions: LH level is an independent factor affecting pregnancy outcome of fresh embryo transfer in DOR patients undergoing GnRH-ant protocol, especially for advanced-aged women. LH had a high predictive value for POSEIDON group 4 patients, and LH ≥ 3.14 IU/L predicts poor pregnancy outcomes.