[Hypothyroidism and hyperprolactinemia]

Abstract

Blood thyrotropic hormone, thyroxin, tri-iodothyronine, FSH, LH, estradiol and progesterone levels were examined in 14 patients with primary hypothyroidism and 11 normal women of reproductive age. All the women under study were subjected to functional tests with intravenous thyroliberin (TRH) and metoclopramide. All hypothyroid patients had anovulatory infertility. Hyperprolactinemia was detected in 8 of 14 patients. It is demonstrated that hyperprolactinemia, developing in cases of primary hypothyroidism, is associated with impaired dopaminergic inhibition of pituitary lactotropics. Substitution thyroidin therapy resulted in the recovery of the normal ovulatory cycle in all but one patient with secondary pituitary microprolactinoma, and 8 patients became pregnant. It is believed that damaged dopaminergic regulation of hypothalamic luliberin (RH) secretion is a direct cause of ovarian dysfunction associated with primary hypothyroidism.