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

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

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_HCG level and age. The clinical data and outcomes were compared between groups.

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_HCG < 2.58 IU/L group were significantly higher than LH_HCG ≥ 2.58 IU/L group. There was no significant correlation between LH_HCG 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_HCG < 3.14 IU/L group were significantly higher than LH_HCG ≥ 3.14 IU/L group. Logistic regression analysis indicated that LH_HCG 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).

LH_HCG 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_HCG had a high predictive value for POSEIDON group 4 patients, and LH_HCG ≥ 3.14 IU/L predicts poor pregnancy outcomes.