29 pregnancies occurred spontaneously in 28 women with mild to moderate hyperprolactinemia (prolactin levels up to 100 ng/ml). Only 4 of them showed tomographic evidence of microprolactinoma; 1 of the prolactinoma patients experienced a visual field defect at week 30, which was quickly controlled by bromocriptine treatment. Pregnancy was uneventful in the rest of the patients. Subjects who wished to lactate successfully breast-fed their babies. Of 22 women in whom prolactin levels were reevaluated at least 1 month after delivery and/or lactation, normal values were found in 9.