Assessing the impact of basal D2 luteinizing hormone level on blastulation rate in normovarian patients

Objectives: To evaluate the relationship between luteinizing hormone (LH) level on day two of stimulation cycle and its outcome in patients undergoing GnRH antagonist IVF protocol. Materials and Methods: This is a retrospective cohort study conducted in tertiary fertility center. A total of 1263 normovarian women undergoing controlled ovarian stimulation for IVF/ICSI were stratified into four groups based on baseline LH: L1 (<2 mIU/mL), L2 (2–5 mIU/mL), L3 (5.1–10 mIU/mL), and L4 (>10 mIU/mL). Results: Higher: LH levels (L3 and L4) were significantly associated with improved ovarian reserve markers, including anti-Müllerian hormone (AMH) and antral follicle count (AFC). Oocyte yield increased across LH strata (L1: 9.48 vs L4: 17.18), while qualitative indicators such as blastulation rate remained comparable (L1: 54.14% vs L4: 58.59%). Clinical endpoints including biochemical pregnancy, clinical pregnancy, and miscarriage rates did not differ significantly among groups. These findings suggest that elevated LH reflects greater follicular availability without adversely impacting embryo competence or pregnancy success. Conclusion: Baseline LH may serve as an adjunct marker of ovarian reserve, correlating with AMH and AFC, but does not predict clinical pregnancy outcomes. LH should be interpreted alongside other clinical parameters when tailoring stimulation strategies for individualized fertility care.