ABSTRACT
Gestational diabetes insipidus, which occurs rarely during late pregnancy, may injure the mother and fetus neurologically. It takes place in about 4 of every 100,000 pregnancies. Increased placental-derived vasopressinase in late pregnancy markedly degrades vasopressin. The decreased vasopressin activity causes hypotonic polyuria, polydipsia, and dehydration. We report a woman with gestational diabetes insipidus who had no abnormal laboratory tests before developing symptoms. The diabetes insipidus was controlled well by administering nasal desmopressin (1.desamino.8.D.arginine vasopressin, DDAVP) followed by resolution of the signs and symptoms after delivery. Although gestational diabetes insipidus is rare, a prompt diagnosis and appropriate treatment to reduce the risks of maternal and fetal injury are important.