Management of endocrine disorders in pregnancy. Part II. Pituitary, ovarian and adrenal disease.

The scope of the problem of the management of pregnancies occurring in women with pituitary disease is indicated by the fact that 20% ofnon-pregnant women with amenorrhoea have hyperprolactinaemia and 40% of women with hyperprolactinaemia have pituitary tumours (Franks et al., 1975). We concentrate therefore on disturbance of prolactin secretion and discuss other pituitary diseases only briefly. During normal pregnancy, prolactin concentrations in serum rise to levels of 4,000-5,000 miu/l, because of an oestrogen-mediated increase in the number of pituitary lactotrophs and an increase in prolactin secretion. Pituitary prolactin release during pregnancy does, however, remain under dopaminergic control. The high concentration of prolactin in amniotic fluid is due to local production by the decidua, which is not influenced by the factors that determine pituitary prolactin secretion (Jacobs, 1980). After delivery, serum prolactin concentrations fall in parallel with the fall of oestrogen levels but they increase in response to suckling, through activation of the neuro-humeral suckling reflex. During breast feeding, prolactin promotes milk production, but 'let down' is mediated through suckling-induced release of oxytocin.