RESUMEN
To evaluate prospectively the prognostic factors for ovulatory response to letrozole therapy in polycystic ovary syndrome [PCOS]. The IVF and Assisted Reproduction Center in Sana'a, Yemen. Thirty-three infertile patients with anovulatory PCOS were recruited. Ovulation was induced using 2.5 mg/day letrozole administered from day 3 to 7 of the cycle. When the dominant follicle reached a diameter > 18 mm, HCG 10.000 IU was given IM and timed intercourse was advised. Clinical and endocrinal parameters between responder and non-responder groups were analyzed. There was no significant difference between letrozole responders and non-responders as regards to the period and type of infertility, BMI, LH, FS H or LH/FSH ratio and E[2] levels. However, statistically significant differences were found with respect to patient age, menstrual pattern, hirsutism and fasting insulin levels between responders and non-responders to ovulation induction with letrozole in PCO patients. Response of the PCOS patients to ovulation induction by letrozole may be related to patient age, menstrual pattern, presence of hirsutism, and serum insulin levels