BRD2 and ovarian hyperstimulation syndrome: Table 1 shows that age, BMI, duration of infertility, baseline FSH levels, and baseline estradiol levels increased with the POSEIDON group (all P < 0.001), while baseline LH levels, baseline AMH levels, baseline AFC, and the frequency of ovarian hyperstimulation syndrome (OHSS) during the study period decreased with the POSEIDON group (all P < 0.001).