Sixty-nine pregnancies were observed in 57 hyperprolactinemic women (5 with pituitary macroadenoma, 20 with microadenoma, and 32 with normal tomography of the sella turcica). Ten of these pregnancies took place spontaneously in women with mild to moderate hyperprolactinemia (up to 70 ng/ml); 2 were induced by exogenous gonadotropins, 2 by clomiphene, 42 by bromocriptine, and 9 by metergoline; and 4 occurred after pituitary selective adenomectomy. The observed complications included spontaneous abortion (10 cases); headache (7 cases); sellar enlargement (5 cases); and bitemporal hemianopsia (1 subject with macroadenoma). Among 24 women in whom prolactin levels were reevaluated at least 1 month after parturition and/or lactation, 8 showed a decrease in prolactin concentration (less than 50% of pregestational levels), with actual prolactin normalization in 3 and resumption of cyclic menses in 2 previously amenorrheic women. In contrast, no changes in prolactin levels occurred after pregnancies that ended in abortion. These data suggest the following: 1) conception is not uncommon in women with moderate hyperprolactinemia; and 2) pregnancy may be safely induced without prior surgery and/or radiotherapy in hyperprolactinemic women, except those with large pituitary adenomas, and a considerable number of these patients even show a clinical and biochemical improvement after pregnancy.