*Data presented as Mean ± SD (interquartile range), independent samples t test, **Data presented as n (%), Mann-Whitney test. PCOS: Polycystic ovarian syndrome, OHSS: Ovarian hyperstimulation syndrome, BMI: Body mass index, FSH: Follicle-stimulating hormone, LH: Luteinizing hormone, E2: Estradiol. This evidence concerns the gene BRD2 and ovarian hyperstimulation syndrome.