Patients with pituitary adenoma had a significantly higher (p less than 0.001) baseline serum prolactin level (182 +/- 4.6 ng/ml) than those with no adenoma (59.2 +/- 4.2 ng/ml). All patients in the study were treated with bromocriptine (2.5-10 mg) to normalize serum prolactin or to achieve a pregnancy.