Prolactin secretion in women: narrative review

The aim of this review is to explore relevant aspects of prolactin physiology and the conditions associated with hyperprolactinemia in women. PubMed and Google Scholar were queried using pertinent keywords to retrieve relevant studies with a particular focus on prolactin physiology, hyperprolactinemia, macroprolactinemia, prolactinoma, and general conditions that may displays alterations of prolactin secretion. Circulating prolactin displays a circadian cycle that disappears during pregnancy, hyperprolactinemia, and prolactinoma. Prolactin is under dopaminergic control and the influence of estrogens during reproductive years. Physical activity is a powerful stimulus for the pituitary release of prolactin. During pregnancy circulating prolactin increases and is present in the amniotic fluid. During lactation, the principal stimulus for prolactin secretion is breast suckling. Hyperprolactinemia may be related to functional causes or due to the presence of tumors producing prolactin (prolactinoma). Hyperprolactinemia may correspond to excessive production of normal (monomeric) prolactin or polymeric molecules (macroprolactinemia). The use of polyethylene glycol may differentiate the presence of those forms of prolactin. Functional hyperprolactinemia may be treated with dopaminergic agents like bromocriptine or cabergoline. The majority of cases of hyperprolactinemia associated with pituitary tumors correspond to microprolactinomas that may be treated with the same drugs. Macroprolactinoma may be treated with the same compounds, although surgical excision may be needed in some cases. These drugs should be interrupted during pregnancy unless prolactinoma grows or expand out of the sella turcica. A prolactin fragment has been related to the rare peripartum cardiomyopathy that appears during the last month of pregnancy or within the initial five months after delivery. Hyperprolactinemia has been also associated with an increased risk of subclinical atherosclerosis.