The anovulatory patient who produces estradiol and gonadotropins but does not cycle. The anovulatory woman who is deficient in estrogen and gonadotropins and as a result cannot cycle. The normally ovulating woman who needs multiple follicular growth to undergo an IVF program. To date, the main agents used for the induction of ovulation are clomiphene citrate, GnRH-analogs and gonadotropins. Clomiphene citrate Clomiphene citrate is an orally active, non-steroidal agent which is distantly related to diethylstilbestrol.
Clomiphene exerts only a very weak biologic estrogenic effect.
The structural similarity to estrogen, however, is sufficient to achieve uptake and binding by estrogen receptors including those of the hypothalamus. The hypothalamus acts on the false information that the estrogen level in circulation is low, FSH and LH levels increase and this stimulates follicular growth. Several factors can account for this difference, the main one probably being the high level of chromosomally abnormal oocytes following clomiphene induction of ovulation. Therapy can also be used to manipulate the cycle but administration beyond day 9 may have no effect. Ovulation usually occurs in the interval 5 to 10 days after the last day of medication.