Ovarian stimulation in polycystic ovary syndrome patients: the role of body mass index

In an attempt to examine whether body mass index (BMI) may influence IVF outcome in polycystic ovary syndrome (PCOS) patients undergoing ovarian stimulation with either gonadotrophin-releasing hormone (GnRH)-agonist (agonist group) or antagonist (antagonist group), 100 IVF cycles were studied: 35 in the agonist and 65 in the antagonist groups. In both agonist and antagonist groups, patients with BMI ≤ 25 kg/m2 had a significantly higher fertilization rate compared with patients with BMI > 25 kg/m2 (P < 0.02 and P < 0.01, respectively). Lean patients (BMI ≤ 25) undergoing ovarian stimulation using the GnRH-agonist, demonstrated the highest pregnancy rate. In conclusion, in this series of PCOS patients undergoing IVF-embryo transfer cycles, ovarian stimulation utilizing the midluteal long GnRH-agonist suppressive protocol yielded a higher pregnancy rate in lean patients, probably due to its ability to lower the high basal LH milieu and its detrimental effect on oocyte quality and implantation potential.