Ovarian superstimulation for in vitro embryo production based on Anti-Müllerian hormone phenotype: Effect of FSH dose schedule.

Anti-Müllerian hormone (AMH) is positively associated with embryo production, yet it also reflects underlying physiological variability. While follicle-stimulating hormone (FSH) is typically administered using a decreasing dose schedule, the effects of alternative dosing strategies on in vitro embryo production (IVEP) outcomes remain unclear. This study aimed to evaluate the impact of FSH dose schedule on IVEP outcomes in the context of differing AMH concentrations. Pregnant heifers (n = 22) received 350 IU of FSH across six administrations using decreasing, constant, or increasing dose schedules in a crossover design. Superstimulation began at follicular wave emergence, and cumulus-oocyte complexes (COCs) were retrieved 44 h after the last FSH dose and subjected to IVEP. Circulating AMH was positively associated with total follicle number, whereas follicle count did not differ by treatment (P ≥ 0.20). The increasing dose schedule tended (P ≤ 0.10) to yield more COCs and resulted in a greater COC retrieval percentage (P = 0.02) than the decreasing schedule. Both COC number and retrieval percentage were positively associated with AMH (P ≤ 0.03), independent of dose schedule. Greater AMH was linked to greater cleavage (constant and decreasing, P < 0.01) and blastocyst percentages (constant only, P < 0.01), while both parameters decreased with AMH under the increasing schedule (P ≤ 0.05). Despite these interactions, blastocyst yield was unaffected by FSH dose schedule (P = 0.84) but was positively associated with AMH (P < 0.01). In conclusion, AMH was predictive of IVEP outcomes regardless of FSH dose schedule, and use of a constant dose schedule may simplify donor management without compromising embryo yield.