The purpose of this study is to determine whether letrozole combined with gonadotropins are effective in the ovarian hyperstimulating for IVF/ICSI in patients with PCOS.

Polycystic ovarian syndrome (PCOS) occurs in 4% to 7% of all women of reproductive age and 20% of women presenting with anovulatory infertility. A significant proportion of these women will ultimately need assisted reproductive techniques. Various protocols of ovarian stimulation such as step up protocol, coasting, GnRH antagonists et al have been proposed for optimizing IVF results in patients with PCOS. The results of these studies have shown it not to be satisfied. The preliminary studies have proven that Letrozole, a potent and highly specific nonsteroidal aromatase inhibitor, could successfully induce ovulation in women with polycystic ovary syndrome. In spite of only a little study research of letrozole in IVF/ICSI cycle, for poor ovarian responders, addition of letrozole improved ovarian response to FSH and reduced gonadotrophin dose required for COH without having a negative impact on pregnancy rates. These reports prompted us to hypothesize that adjunctive use of letrozole in COH protocol for patients with PCOS would minimize the gonadotrophin dose, and consequently the cost, and lower the risk of OHSS in a IVF/ICSI treatment cycle.

Inclusion Criteria:

• patients with PCOS