GnRHa trigger and individualized luteal phase hCG support according to ovarian response to stimulation: two prospective randomized controlled multi-centre studies in IVF patients

Although a non-significant result, one bolus of 1.500 IU hCG after GnRHa trigger tended to reduce the OHSS rate in patients with 15-25 follicles ≥11 mm as well as secure the ongoing pregnancy rate. In contrast, in patients at low risk of OHSS the administration of two boluses of 1.500 IU hCG after GnRHa trigger should be avoided as it may induce OHSS.