Relationship of weight to successful induction of ovulation with clomiphene citrate.

Over a 6 1/2-year period, 117 patients who were anovulatory, euthyroid, and estrogen-primed were treated with clomiphene citrate. Graduated doses from 50 mg to 250 mg daily for 5 days were used to induce ovulation. Of 62 patients who completed treatment, 50 ovulated and 12 did not. Several factors, including age, duration of infertility, weight, previous menstrual history, previous pregnancy history, and previous use of oral contraceptives, were investigated to determine conditions which might influence response. Only weight was found to be significantly different between responders and nonresponders. Furthermore, there was a linear relationship between body weight and dose of clomiphene required to induce ovulation. The ovulation rate for those completing therapy was 81% with a pregnancy rate of 76% of the total and 94% of those ovulating. Population homogeneity with anovulation as the major cause of infertility appears to be the most plausible explanation for the high pregnancy rate.