Therefore, we sought to characterise clinical parameters of OHSS (ovarian volume, ascitic volume) and symptoms of OHSS following different triggers of oocyte maturation (hCG, GnRHa or kisspeptin) in women at high risk of early OHSS (antral follicle count or total number of follicles on day of trigger ≥23). Here, KISS1 is linked to ovarian hyperstimulation syndrome.