The use of GnRH agonist triggers is associated with lower rates of OHSS than following hCG, however, recent case reports suggest that use of GnRH agonist triggers, even in the absence of supplemental hCG for luteal phase support and with segmentation, does not eliminate the occurrence of severe OHSS in high-risk populations (22, –, 24). This evidence concerns the gene GNRH1 and ovarian hyperstimulation syndrome.