Influence of bromocriptine on plasma levels of prolactin and steroid hormones in the 20th week of pregnancy

Medical versus surgical treatment of prolactinomas: an analysis of treatment outcomes

INTRODUCTION

Prolactinomas are unique tumors that may go into both hormonal and radiographic remission with dopamine agonist therapy or transsphenoidal surgery. Regardless of modality, the goals of therapy remain the same: (1) biochemical remission, including reduction of prolactin and normalization of sex hormones; (2) radiographic tumor control, with a range including prevention of tumor growth, tumor regression, or complete tumor resolution; (3) resolution of preoperative symptoms, including those that are hormonal or neurologic; and (4) prevention of new hypopituitarism or new neurologic symptoms.

AREAS COVERED

In the following review, we performed a search of the literature using keywords 'prolactinoma,' 'dopamine agonist,' 'surgery,' 'cost-effectiveness,' 'recurrence,' and 'complication' to compare the relative merits of medical versus surgical therapy for prolactinoma, including special circumstances such as cystic tumors, pregnant patients, and the cost-effectiveness of different strategies.

EXPERT COMMENTARY

Medical therapy can offer a cure, but surgery provides an important adjunct to patients with resistance or intolerance to dopamine agonists, and offers excellent outcomes including when combined with continued postoperative medical therapy. Further head to head comparisons will benefit patients and practitioners weighing the relative risks and benefits of medical and surgical intervention, including the issue of their relative cost-effectiveness.

Prolactinoma through the female life cycle

Prolactinomas are the most common secretory pituitary adenoma. They typically occur in women in the 3rd-6th decade of life and rarely in the pediatric population or after menopause. Most women present with irregular menses and/or infertility. Dopamine (DA) agonists, used in their treatment, are safe during pregnancy, but in most cases are discontinued at conception with close monitoring for signs or symptoms of tumor growth. Breastfeeding is safe postpartum, provided there was no significant growth during pregnancy. Some women will experience normalization of prolactin levels postpartum. Menopause may also decrease prolactin levels and even those with macroprolactinomas may consider discontinuing their DA agonist with close follow-up. Prolactinomas may be associated with decreased quality of life scores in women, and play a role in bone health and cardiovascular risk factors. This review discusses the current literature and clinical understanding of prolactinomas throughout the entirety of the female life cycle.

Endocrinology in pregnancy: management of the pregnant patient with a prolactinoma

A woman with a prolactinoma is usually infertile. Dopamine agonists usually restore ovulation and fertility and such treatment generally is preferred over transsphenoidal surgery because of higher efficacy and safety. Cabergoline is usually preferred over bromocriptine because of its better efficacy with fewer adverse effects. Either drug increases the rates of spontaneous abortions, preterm deliveries, multiple births, or congenital malformations over what may be expected. However, the number of pregnancies reporting such experience is about sevenfold greater for bromocriptine. Tumor growth causing significant symptoms and requiring intervention has been reported to occur in 2.4% of those with microadenomas, 21% in those with macroadenomas without prior surgery or irradiation, and 4.7% of those with macroadenomas with prior surgery or irradiation. Visual fields should be assessed periodically during gestation in women with macroadenomas. If significant tumor growth occurs, most patients respond well to reinstitution of the dopamine agonist. Delivery of the baby and placenta can also be considered if the pregnancy is sufficiently advanced. Transsphenoidal debulking of the tumor is rarely necessary.

Prolactinoma in pregnancy

Prolactinomas commonly cause infertility and treatment usually restores ovulation and fertility. The dopamine agonists are the preferred mode of treatment, with cabergoline generally being preferred to bromocriptine because of its higher therapeutic ratio. Experience with both drugs shows no increase in spontaneous abortions, preterm deliveries, multiple births, or congenital malformations, compared to what is expected in the normal population but the experience with bromocriptine is approximately 10-fold greater than with cabergoline. Clinically significant tumor growth may occur in 2.7% of those with microadenomas, 22.9% in those with macroadenomas without prior ablative treatment and 4.8% of those with macroadenomas with prior ablative treatment. Patients with macroadenomas should have visual fields assessed periodically during gestation. Should symptomatic tumor growth occur, reinstitution of the dopamine agonist is usually successful in shrinking the tumor but delivery if the pregnancy is sufficiently advanced is also an option and transsphenoidal debulking is rarely necessary.

The safety of bromocriptine in hyperprolactinaemic female infertility: a literature review

The dopamine agonist bromocriptine has been widely used to facilitate pregnancy in hyperprolactinaemic women, with a success rate of 80% in relevant cases. Neither the inappropriate hyperprolactinaemia consequent upon bromocriptine withdrawal after conception nor the relative hypoprolactinaemia caused by treatment throughout gestation appears to affect adversely the course and outcome of pregnancy or the endocrine status of the fetus. No teratogenic effect of bromocriptine has been evidenced in humans, and no disturbances in the physical, psychomotor, and intellectual development of the offspring have been observed. Pituitary-tumor enlargement during closely supervised pregnancies very rarely leads to severe and irreversible complications; both the re-institution of bromocriptine treatment in the event of tumor enlargement and its preventive use throughout pregnancy have been shown to be effective measures. It is interesting, moreover, that a reduction of hyperprolactinaemia, compared with pregestational levels, may be seen after bromocriptine-facilitated pregnancies.

Prophylactic bromocriptine treatment during pregnancy in women with macroprolactinomas: report of 13 pregnancies

Ten women with a macroprolactinoma had prophylactic bromocriptine treatment during 13 pregnancies in the second and third trimesters. One patient had signs of tumour enlargement during the first trimester, but none of them showed tumour enlargement during prophylactic bromocriptine treatment. Prolactin levels were reduced in both maternal and cord sera, but they were normal in amniotic fluid. All pregnancies progressed to term. Thirteen healthy infants were born without congenital malformations and growth and psychomotor development were normal during the follow-up period (7 months to 5 years). The safety of bromocriptine treatment during pregnancy is discussed and our current policy of management of patients with prolactinomas is outlined.

Pregnancy in hyperprolactinemic women

Pregnancy achieved in women who receive treatment to correct the secretory dysfunction of nontumoral HPRL or microprolactinomas requires close prenatal care, but generally its course does not vary from normal. When a macroprolactinoma is present, consequences of pregnancy are insignificant, provided the tumor has been previously treated or bromocriptine is given continuously during the pregnancy. On those rare occasions when symptoms of tumor growth appear during pregnancy, bromocriptine and dexamethasone effectively control such manifestations. Breast-feeding of the infant can be allowed, and a second pregnancy within a short term is not contraindicated. When a new pregnancy is not desired, nonhormonal contraceptive methods are advised. Patients with nontumoral HPRL and microadenomas require periodic checkups. Macroadenomas may be surgically excised, but longterm bromocriptine treatment also achieves good results and is highly recommended.

Effect of metoclopramide on maternal and fetal hyperprolactinemia

To investigate the effect of metoclopramide (MET), a dopaminergic antagonist drug, on serum PRL concentration in maternal and cord blood (CB) serum, the drug was injected in 94 at term pregnant women whereas 28 mothers received saline. Maternal serum (MS) samples were obtained before MET injection and at the parturition time. According to the interval of time between MET administration and birth, MS specimens were grouped in 7 groups. CB was obtained from neonates whose mothers were injected with saline, group 0 and from newborns whose mothers were treated with MET, groups 1 to 7. In the 7 groups of women the mean PRL concentration before MET ranged between 307 and 439 ng/ml. After MET injection a significant increase has been observed in all groups with a minimum and maximal mean value of 639 and 931 ng/ml. The highest net increment of PRL has been measured in group 1 sampled at 5 to 30 minutes after MET. CB PRL concentration in group 0, saline treated, was not different from the values measured in group 1 to 7, treated groups, with a range between 504 and 703 ng/ml. These findings suggest that maternal lactotropes are still responsive to MET. On the opposite, fetal pituitary does not release PRL after MET injection probably because PRL secretory activity is maximal or because the dopaminergic receptors' system is still immature.

Maternal serum hormone changes during abortion induced with 9-deoxo-16, 16-dimethyl-9-methylene prostaglandin E2

Serum hormone levels in women undergoing successful first and second trimester abortions induced by 9-deoxo-16, 16-dimethyl-9-methylene prostaglandin E2 vagitories have been measured. Significantly decreased levels of prolactin (p less than 0.01) and TSH (p less than 0.05) were seen in both groups of women but the drop appeared sooner, within two hours, in first trimester abortions. Regardless of gestational length there was a significant decrease in serum human chorionic gonadotropin (hCG) (p less than 0.01) concentrations in maternal serum six hours into treatment. In the second trimester abortions total estriol, alpha-fetoprotein and lactoplacental hormone hPL were analysed in maternal serum but the levels did not change over the eight hour investigation period. It is speculated that the PGE2-derivative most likely affects the maternal pituitary secretion of prolactin and TSH, possibly via direct or indirect interference with TRH mechanism(s).