Pituitary function tests in Sheehan's syndome.

Fourteen patients with a typical history of Sheehan's syndrome underwent pituitary function tests with simultaneous injections of 100 micrograms LH-RH, 200 micrograms TRH and 0.05--0.1 units of soluble insulin per kg body weight. Serum prolactin levels remained unchanged in all of eleven subjects given TRH. GH levels did not rise after hypoglycaemia in five subjects. In contrast serum LH and FSH rose significantly in twelve out of fourteen subjects given LHRH and serum TSH rose significantly in five out of seven subjects given TRH. It is concluded that pituitary function is relatively preserved for LH and FSH but not for prolactin and GH in Sheehan's syndrome. It is further suggested that absence of a rise in prolactin following TRH stimulation may provide the most sensitive test of pituitary hypofunction in postpartum haemorrhage.