Preretrieval predictors of pregnancy in IVF

This study was designed to evaluate the predictive value of preretrieval parameters of ovarian stimulation in patients undergoing IVF-ET.

Women diagnosed with infertility due to tubal factor were compared to women with other and/or multiple diagnoses. Stepwise logistic regression evaluated 389 cycles to identify the best predictors of pregnancy among the following variables: age, primary or secondary infertility, cycle number, type and dose of gonadotropin, duration of gonadotropin administration, serum estradiol level, and number and size of follicles.

In the tubal disease group, probability of pregnancy was greater in cycles with serum estradiol levels below 1100 pg/ml on the day of hCG (odds ratio, 4.7) and with administration of gonadotropins for less than 10 days (odds ratio, 3.7). In contrast, in the other/mixed diagnoses group, a serum estradiol below 1100 pg/ml was associated with a decreased probability of pregnancy (odds ratio, 0.6).

Optimal parameters of ovarian stimulation may vary according to the etiology of infertility. In patients with tubal disease, the beneficial effects of greater stimulation, and thus the greater number of available oocytes, may be offset by adverse effects on the endometrium and on the quality of oocytes and embryos. In contrast, in other diagnostic groups, the advantage of an increased number of oocytes may outweigh the potential adverse effects of prolonged stimulation and higher estradiol levels.