Diabetes insipidus in pregnancy.

Diabetes insipidus (DI) and pregnancy may coexist and, when they do, present challenging diagnostic and therapeutic problems. Women with preexisting central DI usually experience increased thirst and require additional hormone replacement. Women with nephrogenic DI have an increased water turnover. Of interest is a group of women with transient DI of gestation. In some of these patients, central DI is brought to the fore by increases in water turnover during pregnancy as well as increments in the metabolic clearance of arginine vasopressin (AVP), especially near term. Others have a "vasopressin-resistant" form of the disease, which in one case followed by us appeared to be due to marked increments in circulating cystine-aminopeptidase (vasopressinase). This patient's DI was resistant to pitressin, but she concentrated her urine when given dDAVP. Her vasopressinase levels 2 weeks postpartum were still several-fold those of normal term gravidas. Her DI remitted, and she concentrated her urine appropriately 2 months postpartum. This article reviews the different forms of DI peculiar to pregnancy.