ABSTRACT
Sheehan’s syndrome is a postpartum emergency involving loss of pituitary function. The syndrome develops from ischemic necrosis of the pituitary gland after severe postpartum hemorrhage. Pituitary apoplexy is an emergent condition consisting of pituitary hemorrhage which can occur in pregnancy or the postpartum period. The most immediate danger to the patient from either emergency is the risk of adrenal crisis as the loss of adrenocorticotropic hormone signal from the pituitary gland to the adrenal glands leads to a sudden deficit of cortisol. Severe, potentially fatal hypotension can ensue. With pituitary necrosis or hemorrhage, thyroid-stimulating hormone levels decline as well and stimulation of thyroid hormone production by the thyroid gland becomes negligible. The long half-life of thyroid hormone means that circulating thyroid hormone will decline slowly over time, with symptoms of central hypothyroidism developing over many weeks to months. If left untreated, deficiencies of cortisol and thyroid hormone are fatal. Although Sheehan’s syndrome or apoplexy may lead to only partial or mild dysfunction of the pituitary gland, maintaining a high suspicion for central adrenal insufficiency in a pregnant or postpartum woman who remains hypotensive after volume replacement, and treating her appropriately with glucocorticoid replacement, can be life-saving.
