Additionally, large multicenter studies of women with a similar age range as here, such as the Menopur in GnRH Antagonist Cycles with Single Embryo Transfer (MEGASET) study [23] using follitropin beta, reported 1.6% early-onset moderate/severe OHSS compared to here overall 1.9% moderate/severe OHSS with Ovaleap®, and in the recent Evidence-based Stimulation Trial with Human rFSH in Europe and Rest of World (ESTHER-1), utilizing follitropin delta and comparing to follitropin alfa in a GnRH antagonist protocol, the overall incidence of moderate/severe OHSS for follitropin alfa was 2.9% [24]. This evidence concerns the gene GNRH1 and ovarian hyperstimulation syndrome.