Obesity and Clomiphene Challenge Test as predictors of outcome of in vitro fertilization and intracytoplasmic sperm injection

One hundred and sixty-two consecutive patients undergoing in vitro fertilization (IVF) or IVF/intracytoplasmic sperm injection (ICSI) were studied to determine the effect of obesity on the outcome of this treatment and to evaluate the prognostic value of the Clomiphene Challenge Test (CCT) in controlled ovarian hyperstimulation. In this prospective clinical study, we assessed the mean number of stimulation days, the mean gonadotropin level/day, cancellation rate, the mean thickness of the endometrium, the mean number of oocytes retrieved, the fertilization rate, the clinical pregnancy rate/embryo transfer and the abortion rate. Obese women had a doubled risk of cancellation due to poor response, although this was not statistically significant. Furthermore, they showed up to 45% lower fertilization rates compared to women of normal weight. The CCT was a good predictor of IVF and IVF/ICSI outcome. Women with an abnormal CCT needed more days of stimulation and higher doses of gonadotropins to reach an adequate stimulation, but still overall results were less than in women with a normal CCT. We conclude that obesity negatively affects IVF and IVF/ICSI outcome, and that CCT is a useful prognosticator of response to ovarian stimulation. Obese patients show a tendency to experience more cancellation due to poor response and lower fertilization rates. Obese women should be counseled on their possible poor performance in IVF and IVF/ICSI programs. Copyright (C) 2005 S. Karger AG, Basel.