GNRH1 and ovarian hyperstimulation syndrome: Despite the absence of OHSS cases in the Progestin Group, there were two cases in the Control Group, with no statistically significant difference.( 26 ) Barbosa et al., reported a 5% prevalence of OHSS in Brazilian patients who used 200IU per day of rFSH associated with ant-GnRH.( 19 ) Induction of ovulation also deserves consideration.