Sheehan's syndrome.

Sheehan's syndrome occurs as a result of ischemic pituitary necrosis due to severe postpartum hemorrhage. It may be rarely seen without massive bleeding or after normal delivery. Improvement in obstetric care and availability of rapid blood transfusion coincided with a remarkable reduction in the frequency of Sheehan's syndrome particularly in western society. But it has recently been reported more often from well-developed countries. It is one of the most common causes of hypopituitarism in underdeveloped or developing countries. Enlargement of pituitary gland, small sella size, disseminated intravascular coagulation and autoimmunity have been suggested to play a role in the pathogenesis of Sheehan's syndrome in women who suffer from severe postpartum hemorrhage. The patients may seek medical advice because of various presentations ranging from non-specific symptoms to coma and the clinical manifestation may change from one patient to another. Failure of postpartum lactation and failure to resume menses after delivery are the most common presenting symptoms. Although a small percentage of patients with Sheehan's syndrome may cause abrupt onset severe hypopituitarism immediately after delivery, most patients have a mild disease and go undiagnosed and untreated for a long time. It may result in partial or panhypopituitarism and GH is one of the hormones lost earliest. The great majority of the patients has empty sella on CT or MRI. Lymphocytic hypophysitis should be kept in mind in differential diagnosis. In this review, the old and recent data regarding Sheehan's syndrome are presented.