Effects of exogenous LH administration during ovarian stimulation of pituitary down-regulated young oocyte donors on oocyte yield and developmental competence.

BACKGROUND The role of exogenous LH supplementation in ovarian stimulation is a matter of debate. Here we evaluate the impact of exogenous LH on oocyte yield and developmental competence in an oocyte donation programme. METHODS Oocyte donors were randomized (computer-generated randomization list) to groups stimulated with FSH alone or with a combination of FSH and LH after pituitary down-regulation with a GnRH agonist administered in the mid-luteal phase. RESULTS In donors with deep suppression of pituitary LH (<1 IU/l) before the beginning of ovarian stimulation, the inclusion of exogenous LH resulted in an increase in the number of mature oocytes and good-quality zygotes and embryos as well as higher implantation rates when compared with stimulation with FSH alone. In contrast, the inclusion of exogenous LH in the stimulation of donors with pre-stimulation serum LH of >or=1 IU/l impaired embryo morphology and lowered the implantation rate, although it increased the number of metaphase II oocytes. CONCLUSIONS The inclusion of exogenous LH to the ovarian stimulation protocol can have beneficial or detrimental effects on oocyte yield and quality, depending on the level of endogenous LH. These data support the concept of a 'window' for LH requirement in ovarian stimulation.