Predictors of ovarian response in intrauterine insemination patients and development of a dosage nomogram

The objective of this prospective study was to identify predictors of ovarian response in ovulatory patients treated with low-dose recombinant FSH (rFSH), gonadotrophin-releasing hormone antagonist and intrauterine insemination (IUI), and to develop an rFSH dosage nomogram based on the findings. Patients (n = 159) were stimulated with a starting dose of 75 IU rFSH/day. Ten parameters were investigated as possible predictors of the number of mature follicles ≥15 mm: age, spontaneous cycle length, body weight, body mass index, smoking status, total ovarian volume, total number of antral follicles, total Doppler score of the ovarian stromal blood flow, baseline FSH and oestradiol. Simple and multiple linear regressions were used for the statistical analysis. Appropriate ovarian response was defined as two to three mature follicles. Body weight (P = 0.001) and the number of antral follicles (P = 0.004) were the strongest independent predictive factors of the number of mature follicles. In conclusion, body weight and antral follicle count may be used to achieve appropriate ovarian response for IUI in ovulatory patients. Based on this, a simple rFSH dosage nomogram was developed for individual ovarian stimulation prior to IUI.