Retrospective study examines LH concentration on trigger day in long-protocol IVF/ICSI cycles

This retrospective cohort study analyzed 9,979 IVF/ICSI cycles to investigate the impact of endogenous luteinizing hormone (LH) concentration on the day of hCG trigger during a long GnRH agonist protocol. The population was divided by age, with 8,786 cycles from women younger than 38 years and 1,193 cycles from women aged 38 years or older. The exposure was serum LH concentration, which was stratified into five groups for analysis. The study setting, comparator groups, primary and secondary outcomes, and duration of follow-up were not reported. The main results, including specific numerical data on clinical pregnancy, live birth, or other endpoints, were not provided in the available evidence. Safety and tolerability data, including adverse events and discontinuation rates, were also not reported. Key limitations inherent to the retrospective design, such as potential for confounding and selection bias, were not detailed. The funding sources and author conflicts of interest were not disclosed. The direct practice relevance of these findings remains unclear without reported outcome data, and the observational nature of the evidence precludes causal inference about optimal LH levels.