Induction of ovulation with clomiphene and estradiol benzoate in anovulatory women refractory to clomiphene alone.

Twenty-two infertile and clomiphene-nonresponding patients received a course of clomiphene, 100 mg/day for 5 days, followed 7 days later by an intramuscular injection of 1 mg of estradiol benzoate. The diagnosis of idiopathic chronic anovulation had been established. None of these patients had galactorrhea, hirsutism, or ovarian enlargement. Thirteen of the twenty-two women had surges of both luteinizing hormone and follicle-stimulating hormone after the estradiol injection; the peak gonadotropin levels occurred within 72 hours of the injection. These 13 patients ovulated and pregnancy ensued in 10 of them. The estradiol benzoate injection also elicited a significant increase in serum prolactin levels- This enhanced prolactin release had no apparent effect on the gonadotropin surge. These results suggest that the association of clomiphene and estradiol benzoate potentiates the action of clomiphene and may prove useful in clomiphene nonresponders.