The effect of rLH supplementation to the GnRH-antagonist protocol on endocrine dynamics in the advanced reproductive age

Purpose: To explore serum endocrine dynamics, specifically LH levels, following rLH supplementation to rFSH following GnRH-antagonist treatment in the advance reproductive age. Methods: Women were prospectively and similarly treated employing rFSH and the flexible GnRH-antagonist protocol, while rLH was supplemented only to the study group. Serum FSH, LH, E_2, and P were evaluated throughout the follicular phase. Three strategies were a priori planned to examine endocrine dynamics among women enrolled. Results: While serum LH drop were similar before GnRH-antagonist stimulation, it dropped more times in the control group compared to the study group. Among women receiving rFSH only, serum LH levels dropped ≤2, ≤1 and ≤0.5 mIU/mL in 71.4, 46.4, and 28.6% of cases, while this occurred only in 38.7% (P = 0.01), 6.5% (P = 0.0004) and 3.2% (P = 0.007) of women receiving combined rFSH and rLH treatment, respectively. The same trend was found when serum LH dropped in at least two occasions following the GnRH-antagonist administration. Conversely, serum LH diagrams throughout the follicular phase did not differ between the two groups. Furthermore, individual area under the curve values of LH, E_2, and P was similar between the two groups following GnRH-antagonist initiation. Conclusions: Different strategies to explore LH dynamics following the GnRH-antagonist administration have resulted in diverse results, implying the need for a consensus definition of LH threshold for adequate folliculogenesis and steroidogenesis. Such action would pave the way for understanding which groups of patients may benefit from rLH supplementation.