[Diabetes insipidus and postpartum anterior hypophyseal insufficiency]

There have only been thirty cases of total post-partum hypopituitarism published in the literature and these have nearly all been secondary to Sheehan's syndrome. The authors report a case of partial anterior hypopituitarism associated with diabetes insipidus which arose after an uneventful Caesarean operation and the origin of which seems to lie in auto-immune hypophysitis. The authors first describe the morphological and endocrine changes that the hypophysis undergoes during pregnancy and then point out that auto-immune hypophysitis seems to have been only recently recognised. This can be used to explain some cases of post-partum hypophyseal insufficiency occurring almost silently without any history of third haemorrhage. Research has been made systematically for anti-hypophyseal antibodies and for specific antibodies of the organ, but has not always been positive. So the diagnosis of auto-immune hypophysitis is often made only after eliminating other reasons for it. A brief review of the physiopathological mechanisms of diabetes insipidus makes it possible to suggest that vasopressinase coming from the placenta together with prostaglandins could play a role.