Obesity and its impact on ovarian stimulation

Abstract

Increased body mass index (BMI) has effect on various aspects of infertility treatment and assisted reproductive technology (ART) procedures. The extent of this influence is, however, conflicting in literature. Overweight and obese women require a higher dose of gonadotropin with greater number of days of stimulation and yet have lower peak oestradiol levels with an increased risk of cycle cancellation due to poor follicular development. On controlled ovarian stimulation, there is less number and poor quality of oocytes reported in these women. They have lower fertilization and pregnancy rates. The effect of obesity upon implantation rate has also been inconsistently reported. Some studies have identified a reduction in implantation rates among the obese women. Weight loss results in regularization of the menstrual pattern, a decrease in cancellation rates, an increase in the number of embryos available for transfer, a reduction in the number of ART cycles required to achieve pregnancy and a decrease in miscarriage rates. There are higher obstetric complications with a lower live birth rate in these women. Obesity is a modifiable risk factor. It has an effect on fertility, its treatment and obstetrics outcome. Women with increased BMI should be first encouraged to reduce weight before starting any treatment for infertility or planning conception.