[The effects of pregnancy on prolactin secretion in occulted hyperprolactinemia]

The changes in the maternal prolactin level during pregnancy and puerperium were studied in 14 patients with occulted hyperprolactinemia, 5 patients with functional hyperprolactinemia, and 135 women with normoprolactinemia. All of those with occulted hyperprolactinemia and functional hyperprolactinemia became pregnant through bromocriptine treatment. Higher prolactin levels were noted in occulted hyperprolactinemic patients from the first to second trimester of pregnancy, but in the third trimester prolactin levels fell to the normal control levels. This change completely resembled the change in functional hyperprolactinemic patients. Prolactin secreting capacities after puerperium returned to normal in 4 of the 5 patients with occulted hyperprolactinemia. These 4 became pregnant for the second time without any treatment. However, the other patient, whose prolactin secreting capacity was aggravated after the first puerperium, became pregnant the second time through bromocriptine treatment. These results indicate the following: 1) most cases of occulted hyperprolctinemia which may be due to functional lesions return to normal after pregnancy, 2) in rare cases of occulted hyperprolactinemia, prolactin secretion capacity is aggravated after the pregnancy, 3) it is important to observe the natural history of the patient in the treatment of occulted hyperprolactinemia.