Macroprolactinomas with suprasellar extension: effect of bromocriptine withdrawal during one or more pregnancies

Evolution of macroprolactinomas during pregnancy: A cohort study of 85 pregnancies

OBJECTIVE

Pregnancy in patients with macroprolactinomas has been associated with a higher risk of pituitary tumour growth. However, the incidence and risk factors remain unclear. We aimed to evaluate the evolution of macroprolactinomas during pregnancy and to identify potential risk factors.

DESIGN, PATIENTS AND MEASUREMENTS

This is a two-centre, retrospective, observational study. All patients with macroprolactinomas, treated with a dopamine receptor agonist (DA), and who had at least one pregnancy were included.

RESULTS

There were a total of 85 viable pregnancies in 46 patients with macroprolactinomas. At diagnosis, mean size of pituitary adenomas was 17.9 ± 8.2 mm (10-43 mm) and mean plasma prolactin level was 1012.2 ± 1606.1 µg/L (60-7804 µg/L). Tumour growth-related symptoms were identified 12 times in 9 patients (19.6%) including 3 cases of apoplexy. Restarting, changing and/or increasing DA treatment was effective in 10 cases. Emergency surgery had to be performed twice (due to pituitary apoplexy). Patients with tumour progression tended to present with larger tumours after initial treatment and before pregnancy (9.9 vs 5.9 mm; P = .0504 and 11.5 vs 7.3 mm; P = .0671, respectively), whereas adenoma size at diagnosis did not seem to be a significant factor. The obstetrical outcomes were comparable to the general population.

CONCLUSIONS

Symptomatic growth of macroprolactinoma during pregnancy occurred in 19.6% of medically treated patients. This risk seems higher for patients with poor initial tumour response to the DA treatment. Tumour progression is generally well controlled with medical treatment during pregnancy.

[Prolactinoma: from quest of pregnancy to delivery]

Prolactinoma is the most frequent hormone-secreting pituitary tumor (100 for million patients) and a major cause of both female and male reproductive function disorders. Physician, gynecologist, urologist and sexologist can face this situation during their career. As part of the fertility restoration, treatment gives very satisfactory results. With adequate management, most women are expected to achieve successful pregnancies. The natural history of these tumors during pregnancy depends on their size with a risk of a clinically relevant estimate between 5 to 30 %. Their management is complex, requiring finding balance between effects of pregnancy on tumor growth and potential risks of overtreatment on fetal development. The aim of this study is to discuss the management of prolactinoma on woman before, during and after pregnancy, and to evaluate the medical and surgical alternatives regarding the actual literature.

Hyperprolactinemia and prolactinomas

Any process interfering with dopamine synthesis, its transport to the pituitary gland, or its action at the level of lactotroph dopamine receptors can cause hyperprolactinemia. As described in this article, considering the complexity of prolactin regulation, many factors could cause hyperprolactinemia, and hyperprolactinemia can have clinical effects not only on the reproductive axis. Once any drug effects are excluded, prolactinomas are the most common cause of hyperprolactinemia. The most frequent symptom is hypogonadism in both genders. Medical and surgical therapies generally have excellent results, and most prolactinomas are well controlled or even cured in some cases.

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.

Relative resistance of a macroprolactinoma to bromocriptine therapy during pregnancy

A woman presented with a pituitary macroadenoma with extensive suprasellar extension. Her initial response to bromocriptine therapy was good, allowing subsequent trans-sphenoidal surgical treatment. The tumor grew during pregnancy despite continued bromocriptine therapy, but it returned to prepregnancy size postdelivery. There have been conflicting reports regarding the growth of pituitary tumors in pregnancy. Most recognize that some growth may occur, but only a small percentage of patients are reported to become symptomatic from the growth. Resistance to bromocriptine has been reported in non-pregnant patients. Patients who have had surgery or radiation therapy and did not receive bromocriptine treatment during pregnancy have been reported to have symptomatic growth of their residual tumor. This case demonstrates an unusual tumor that became resistant to bromocriptine during pregnancy, but whose sensitivity to the drug returned postdelivery.