In rodent models, high concentrations of leptin impair the follicle development, ovulation, and oocyte maturation [57], whereas leptin deficient mice (ob/ob) are the animal experimental model to investigate the effects of obesity, and female ob/ob mice develop low numbers of antral follicules resulting in impaired folliculogenesis, reduced ovulation rate, and accelerated apoptosis of granulosa cells [58]. Here, LEP is linked to obesity due to melanocortin 4 receptor deficiency.