This study explored whether genetic factors influence the number of MII oocytes retrieved during ovarian stimulation. Using data from 516 stimulations and analyzing gene variants, specific haplotypes were identified that improved prediction accuracy beyond clinical factors alone. A neural network model including clinical data served as a benchmark, and adding key genetic variants reduced prediction error notably. These genetic factors had a stronger impact on predictions than IVF protocol or PCOS status and, when prior cycle data was unavailable, their influence was comparable to antral follicle count.