Transient gestational diabetes insipidus diagnosed in successive pregnancies: review of pathophysiology, diagnosis, treatment, and management of delivery

Gestational diabetes insipidus (GDI) is a rare disorder characterised by polyuria, polydypsia, and excessive thirst usually manifesting in the third trimester of pregnancy. The etiology is thought to depend on excessive vasopressinase activity, a placental enzyme that degrades arginine-vasopressin (AVP), but not 1-deamino-8-D: -arginine vasopressin (dDAVP), which is a synthetic form. This is a transient syndrome and may be associated with acute fatty liver of pregnancy and preeclampsia. The use of dDAVP in symptomatic cases has been proven as a safe method for both the mother and the fetus during the pregnancy. We report a case of recurrent gestational diabetes insipidus in successive pregnancies, which responded to dDAVP and subsided after delivery.