Obesity, a common clinical manifestation of PCOS patients, is linked to insulin resistance and failure or delayed response to the various COH treatments.The associated health detriments of this major health problem are increased with increasing body mass index (BMI). Data regarding the impact of obesity on IVF cycles outcome is controversial, ranging from studies reporting on no effect of increasing BMI on IVF success rates to those demonstrating a lower cumulative live birth rates in overweight patients. PCOS and assisted reproduction PCOS women with insulin resistance undergoing ovulation induction with gonadotropin have a longer duration of treatment, use a higher total FSH dose, have an elevated cancellation rate and a lower conception rate. Improving insulin sensitivity through both lifestyle and pharmacological intervention were suggested to ameliorate the aforementioned abnormalities, restore ovulation and enhance pregnancy in women with PCOS.