Effects of bromocriptine-induced pregnancy on prolactin-secreting pituitary tumours

Twenty-eight women with hyperprolactinaemia and amenorrhoea received bromocriptine treatment which resulted in 31 term pregnancies. Bromocriptine treatment was stopped as soon as pregnancy was established. Nineteen of the women had radiological signs of a pituitary tumour. The pregnancies were clinically uneventful in all cases except one who developed headache. Post-partum sellar X-ray showed pregnancy-induced enlargement of the pituitary fossa in 4 of the 28 women. Regression of the radiological changes occurred in 3 of the 4 women within 2 years after the delivery. The women with abnormal sellar X-rays had no difference in the mean prolactin levels before treatment and after pregnancy and lactation while all the women with normal sellae had lower prolactin levels after pregnancy than before. Three women resumed regular spontaneous menstruations after pregnancy and lactation but only one conceived again. Thus, serious pituitary tumour complications are rare in hyperprolactinaemic women with bromocriptine-induced pregnancies. The pregnancy does not worsen the condition. Resolution of hyperprolactinaemia after bromocriptine-induced pregnancy is an unfrequent finding.