More recently, kisspeptin, a neuropeptide that stimulates endogenous GnRH release, has been used to safely mature oocytes during IVF treatment even in women at high risk of OHSS (16–18) (see Fig. 1 for diagram illustrating site of action of each agent used to induce oocyte maturation). This evidence concerns the gene KISS1 and ovarian hyperstimulation syndrome.