Hyperprolactinemia and hypogonadism in the human female.

Prolactin is a mammotropic hormone essential for the initiation of lactation. It also influences ovarian function; during hyperprolactinemia hypogonadism occurs. This is true for pathological forms of hyperprolactinemia but also for the early puerperium when there is physiological hyperprolactinemia. Amenorrhea is a better parameter of hyperprolactinemia than galactorrhea. The mechanisms by which prolactin disrupts ovarian function are not as yet fully understood; it probably alters hypothalamic neurotransmitter content through a direct feedback mechanism resulting in a decrease of Gn-RH. However, the direct effect of prolactin-producing pituitary tumors on the capacity of the gonadotrophs or a direct interference of prolactin at the gonadal level are also possibilities. Hyperprolactinemia can be treated very effectively with bromocriptine and this drug appears to have become the favorite form of treatment. In the case of obvious tumors hypophysectomy is indicated. When there are smaller tumors irradiation of the pituitary gland previous to bromocriptine treatment may prevent expansion of the gland during subsequent pregnancy.