GNRH1 and ovarian hyperstimulation syndrome: They also divided the low-risk group of OHSS (follicles ≥11 mm diameter; less than 15 numbers) into 2 groups: group C received a bolus of 0.5 mg GnRH agonist followed by a bolus of 1500 IU hCG on the day of oocyte retrieval and 1500 IU hCG after oocyte retrieval, while group D received 5000 IU hCG at the same time by the trigger.