Background: The aim was to identify independent predictors of ovarian response to recombinant (r)FSH through a multiple regression analysis.
Methods: Prospective study including 145 'standard' patients treated with 150 IU/day of rFSH during their first IVF/ICSI cycle. Down-regulation was achieved with long agonist protocol. The following were examined as possible predictive factors: age, body mass index, cycle length, smoking status and on day 2-5: total ovarian volume, total number of antral follicles (<10 mm), total Doppler score of the ovarian stromal blood flow, serum FSH, LH, estradiol, inhibin B, and testosterone.
Results: Total number of antral follicles, total Doppler score, serum FSH, LH, estradiol, inhibin B, smoking status and cycle length were independent predictors of the number of aspirated follicles. The number of oocytes was predicted by the total number of antral follicles, total Doppler score, serum testosterone and smoking status. In bivariate linear regression analyses ovarian volume was a highly significant predictor of both the number of follicles (P < 0.001) and the number of oocytes (P < 0.001).
Conclusions: Among 12 investigated possible predictive factors in 'standard' patients, the total number of antral follicles and ovarian stromal blood flow assessed by total Power Doppler score are the two most significant predictors of ovarian response. Suggestion for an rFSH dosage normogram is presented.