Pregnancy following thyroid hormone treatment in a patient with amenorrhea-galactorrhea due to primary hypothyroidism.

A 32-year-old female with amenorrhea-galactorrhea due to primary hypothyroidism was treated with thyroid hormones, and serum levels of thyrotropin (TSH), prolactin (PRL), triiodothyronine (T3), thyroxin (T4), and T3 resin sponge uptake (RT3U) were measured throughout the course of treatment. The elevated serum levels of TSH and PRL fell into the normal range following T3 treatment. Subsequently, the menstrual cycle was restored within 1 month, and galactorrhea completely ceased and conception was achieved within 3 months. Desiccated thyroid was administered during pregnancy, and the patient gave birth to a female infant. Impaired secretion of PRL during pregnancy and poor milk secretion with blunted response of PRL to the suckling stimulus during the puerperium were noted.