Managing Prolactinomas during Pregnancy

Abstract

Prolactinomas are the most prevalent functional benign pituitary tumors due to a pituitary micro- or macroadenoma. The majority of patients presents with infertility and gonadal dysfunction. A dopamine agonist (DA) (bromocriptine or cabergoline) is the treatment of choice that can normalize prolactin levels, reduce tumor size, and restore ovulation and fertility. Cabergoline generally preferred over bromocriptine because of its higher efficacy and tolerability. Managing prolactinomas during pregnancy may be challenging. During pregnancy, the pituitary gland undergoes global hyperplasia due to a progressive increase in serum estrogens level that may lead to increase of the tumor volume with potential mass effect and visual loss. The risk of tumor enlargement may occur in 3% of those with microadenomas, 32% in those with macroadenomas that were not previously operated on, and 4.8% of those with macroadenomas with prior ablative treatment. Though both drugs appear to be safe during pregnancy, the data on fetal exposure to DAs during pregnancy have been reported with bromocriptine far exceeds that of cabergoline with no association of increased risk of pregnancy loss and premature delivery. It is advisable to stop the use of DAs immediately once pregnancy is confirmed, except in the case of women with invasive macroprolactinomas or pressure symptoms. This review outlines the therapeutic approach to prolactinoma during pregnancy, with emphasis on the safety of available DA therapy.

Effects of postnatal bromocriptine injection on thyroid function and prolactinemia of rats at adulthood

“…BRO is used in humans to treat a prolactinoma even during pregnancy and weaning (Bernard et al, 2015;Almalki et al, 2015). BRO crosses the the placenta and is transferred by milk.…”

Pregnancy‐induced progressive change of prolactin‐secreting macroadenoma with the development of bitemporal hemianopia and severe headache

“…Based on most previous studies, breastfeeding is not associated with an increased prolactin production or risk of tumor enlargement . Thus, women can safely breastfeed and restart dopamine agonist therapy after cessation of lactation.…”

Management of resistant prolactinoma in infertile lady with successful maternal and perinatal outcome

“…14 Almalki MH et al in 2015 found that the risk of tumor enlargement in pregnancy may occur in 4.8% of those with macroadenomas with prior ablative treatment. 15 In view of the likely chance of tumour recurrence during pregnancy, formal visual field testing in each trimester was performed. Measurement of serum prolactin levels are not recommended as physiological increase in serum prolactin levels during pregnancy do not accurately reflect the changes in tumour growth or activity.…”