(4) investigated the efficiency of GnRH antagonist pretreatment among patients with two intact ovaries, age <39 years, body mass index 18–32 kg/m2, and a normal uterine cavity, excluding polycystic ovary syndrome, severe endometriosis, low ovarian reserve, thyroid disease, diabetes mellitus, significant hyperprolactinemia, and hypogonadotropic-hypogonadism. This evidence concerns the gene GNRH1 and hypogonadotropic hypogonadism.