Serum CA-125 and inhibin B levels in the prediction of ovarian response to gonadotropin stimulation in in vitro fertilization cycles

There is much controversy about the relationship between serum CA-125 levels during in vitro fertilization (IVF) cycles and ovarian function. To evaluate the prognostic value of serum CA-125 and inhibin B measurements in predicting ovarian response to gonadotropin stimulation, we compared the CA-125 and inhibin B levels of poor and normal responders on the first day of ovarian stimulation, on the day of ovulation induction (OI) and at oocyte pick-up. Sixteen patients with poor ovarian response (???3 oocytes, serum estradiol (E₂) ??900?pg/ml at OI) in IVF/intracytoplasmic sperm injection cycles were matched with normal responders (???6 oocytes, E₂ ??1800?pg/ml) by age, spontaneous cycle day-3 follicle-stimulating hormone level and cause of infertility. Inhibin B concentrations were significantly lower at all three time points in poor responders, but CA-125 levels were not. No statistically significant correlation was found between CA-125 levels and any of the clinical or laboratory parameters examined. Thus, CA-125 measurements during stimulation are not useful in predicting or identifying poor ovarian response to gonadotropin stimulation in IVF cycles. The lack of difference in CA-125 concentrations between poor and normal responders and lack of correlation with E₂ or inhibin B levels suggest that ovarian steroidogenesis and other granulosa cell functions do not influence the production of CA-125. Inhibin B, however, seems to predict ovarian response as early as at the start of stimulation.