The randomization will be done after the decision of gonadotrophin (rFSH/hMG) starting dose, and both doctor and patient will be blinded to the randomization until the day of hCG/agonist trigger. Both groups will be stimulated in a short GnRH antagonist protocol. The ovarian stimulation The gonadotrophin stimulation is performed according to the general standards in each of the clinics and can be altered according to the ovarian response with a maximum of 300 IU.