The GnSAF decreases the risk of premature luteinization by its action on endogenous GnRH secretion pattern.8,9 Therefore, in IVF patients at high risk of OHSS, the risk of premature luteinization and cycle cancellation is relatively low, even if GnRH agonists are not used for pituitary downregulation. This evidence concerns the gene GNRH1 and ovarian hyperstimulation syndrome.