Reproductive doctors struggle with low-prognosis ART patients. These patients have distinct biological profiles. Indeed, although women with reduced ovarian reserve have poor ovarian response, hypo-responders have unanticipated low or subpar response to controlled ovarian stimulation despite fulfilling ovarian criteria. These hypo-responders had slower estradiol and follicle growth responses to FSH stimulation, longer stimulations, and/or higher cumulative FSH dosages. Thus, ovarian sensitivity to gonadotropins seems to vary across patients and affects stimulation response. Genetic mutations or SNPs of gonadotropins and their receptors may affect ovarian sensitivity to FSH. Thus, ovarian sensitivity to FSH may increase IVF success rates in low-prognosis individuals and provide new therapeutic options.