Unexpected case of postnatal pancreatitis: first presentation of autoimmune diabetes.

Gestational diabetes mellitus (GDM) is defined as the first onset of glucose intolerance in pregnancy without prior known diabetes. While it is commonly associated with metabolic risk factors such as obesity and hypertension, a small percentage of women with GDM have underlying autoimmune causes, with presence of islet-cell antibodies resulting in autoimmune-mediated destruction of the pancreas. We present a case of idiopathic postpartum pancreatitis precipitating fulminant diabetic ketoacidosis in a patient with otherwise well-controlled GDM during pregnancy, and subsequent findings of positive anti-glutamic acid decarboxylase antibody. This is the first presentation of autoimmune diabetes diagnosed postnatally in a woman who has no previous medical or family history.