Several studies have addressed the issue of the need or convenience of adding LH activity to FSH in ovarian stimulation in IVF/ICSI-ET in order to increase clinical outcomes in IVF/ICSI cycles , but they have not been able to address the role that LH administration plays during the follicular phase of a stimulated cycle for IVF-ET under pituitary suppression. In the case of r-hFSH administration, in normo-gonadotrophic patients, low levels of endogenous LH can persist despite pituitary down-regulation with GnRH analogues. It is known that only 1% of LH receptors need to be occupied to drive adequate ovarian steroidogenesis for reproduction. But the potential benefit of additional exogenous LH supplementation in ART is still controversial .