Clinically, there are several methods used to reduce LH levels in women with PCOS.Pituitary downregulation using GnRH agonists significantly lowers the LH level in women withPCOS (Homburg et al., 1993;Balen et al., 1993a).However, the GnRH agonist long protocol increases the risk of ovarian hyperstimulationsyndrome (OHSS) in women with PCOS compared with the GnRH antagonist protocol. This evidence concerns the gene PLOD1 and polycystic ovary syndrome.