Sonographic assessment of ovarian reserve. Its correlation with outcome of in vitro fertilization cycles

Ovarian reserve is a crucial factor for normal ovarian response and the achievement of pregnancy after in vitro fertilization (IVF). Recently, the study of morphological markers by means of ultrasonographic counting of antral follicles (AFC) has proved useful. The present prospective study included 327 consecutive IVF patients who had a basal ultrasound scan of their ovarian reserve during the early follicular phase and had a first IVF cycle between 1 and 3 months later. We performed 313 ovum pick-ups with a mean of 11.1 ± 7.9 oocytes retrieved. The pregnancy rate per aspiration was 34.5%. Clear and significant differences were observed between normal and low response with respect to AFC, follicle-stimulating hormone (FSH) level and age. We also found that AFC correlated negatively and significantly with age, FSH and LH, and positively and also significantly with the total number of follicles, estradiol level and the number of oocytes retrieved. Using receiver operating characteristic curves, the cut-off value of AFC for poor response was 7 follicles. The value of AFC for predicting pregnancy was lower, although patients with AFC of 8 or more follicles obtained significantly higher pregnancy rates. We consider that AFC should be included in the study of the infertile patient.