It has been suggested that in IVF cycles where GNRH agonist is utilized for final oocyte maturation in patients at risk of ovarian hyperstimulation, pregnancy rates are reduced. We hypothesize that the use of GNRH antagonist reduces pregnancy rates through an effect on the endometrium and not oocyte quality, therefore better results may be obtained by not returning these embryos in a fresh cycle but rather cryopreserving them and returning them to the uterus and a later stage.