Prolactinomas and Pregnancy. In: Bronstein MD, editor. Pituitary Tumors in Pregnancy. Boston: Springer US; 2001. pp. 91-108. [DOI: 10.1007/978-1-4615-1435-0_4]

Prolactin, prolactin disorders, and dopamine agonists during pregnancy

Pituitary disorders, and especially prolactinomas, are not common among pregnant women, though they tend to occur during a woman's years of fertility. The majority of prolactinoma patients present with infertility and menstruation dysfunction; however, prolactinomas are associated with potentially significant morbidity if they remain unrecognized and untreated. Herein, we survey the role of prolactin and prolactinomas in pregnancy while also outlining the therapeutic approach to prolactinoma during pregnancy. The current literature on the impact of dopamine agonists during pregnancy is also reviewed.

Pituitary tumors and pregnancy: the interplay between a pathologic condition and a physiologic status

Pregnancy is becoming a relatively common event in patients with pituitary tumors (PT), due to the increasing availability of medical treatments, which control pituitary diseases associated with the development of PT. However, the presence of PT and its treatment may be a disturbing factor for pregnancy, and pregnancy significantly influences the course and the management of PT. This review summarizes the knowledge about the management of PT during pregnancy and the occurrence of pregnancy in patients with pre-existent PT, focusing on secreting PT characterized by hormonal excess and on clinically non-functioning PT often associated to hormone deficiency, which configure the hypopituitaric syndrome.

Management of pituitary tumors in pregnancy

Pituitary tumors, usually adenomas, account for about 10-15% of all intracranial tumors. Their treatment, which includes surgery, medicine or radiotherapy, either isolated or in combination, aims to halt tumor growth or achieve tumor shrinkage, as well as control hormone hypersecretion or ensure hormone replacement. Such approaches have made pregnancy possible for women with pituitary adenomas. Medical therapy with dopamine agonists is the treatment of choice for most patients with prolactinomas, with surgery reserved for individuals resistant to drugs. On the other hand, surgery before conception is indicated as a first-line approach in patients with acromegaly, Cushing disease or clinically nonfunctioning pituitary macroadenomas. In these patient populations, medical therapy with somatostatin analogues (acromegaly) or drugs that target the adrenal glands, such as metyrapone and ketoconazole (Cushing disease), should be reserved for those in whom surgery is unsuccessful or contraindicated.

Prolactinomas and pregnancy

Prolactinomas are the most frequent pituitary tumors. Treatment of infertility in such tumors usually is very successful. On the other hand, reports of pituitary tumor growth during pregnancy have been described since bromocriptine started to be used. Since then, dopamine agonists (DA) have been increasingly used as the first-choice treatment of prolactinomas, with surgery being reserved for resistance or persistent intolerance to DA or for special situations. More recently other DA, such as quinagolide and cabergoline have shown better tolerance than bromocriptine with similar or greater efficacy. Cabergoline is now the first choice drug but its use in pregnancy is still under evaluation. We followed 71 term pregnancies in women bearing microprolactinomas. Of the 22 patients with previous surgery, none presented symptoms of tumor growth. Of the 41 pregnant patients treated with bromocriptine alone, only one (2.4%) presented with headaches, which regressed with drug reintroduction. Fifty one term pregnancies in patients with macroprolactinomas were followed by us. Of those, 21 were in patients with previous surgery and none of them presented clinical evidence of tumor growth. On the other hand, of the 30 patients treated only with pre-gestational bromocriptine, 11 (37%) manifested complaints related to tumor growth. A non-hormonal contraceptive should be the use along with a DA drug until tumor shrinkage within sellar boundaries has been evidenced. After pregnancy has been confirmed, the DA can be withdrawn and the patient must be closely followed. If tumor expansion is suspected, confirmation can be made through MRI and by visual field testing. Reintroduction of bromocriptine in such cases can lead to tumor reduction and clinical improvement. Surgery can also be employed as treatment for symptomatic tumor growth in pregnancy.