Diabetes insipidus in pregnancy: etiology, evaluation, and management.

OBJECTIVE: To review the approach to a patient with diabetes insipidus during pregnancy.
METHODS: This review examines the normal physiology of water homeostasis, the related changes that occur during pregnancy, and the pathophysiology of diabetes insipidus in pregnancy. Associated complications, evaluation, and management are discussed.
RESULTS: Diabetes insipidus can complicate up to 1 in 30,000 pregnancies. Diabetes insipidus during pregnancy has a variety of causes, some that predate the pregnancy and others that begin during gestation. Polyuria and polydipsia can occur or be exacerbated in women with overt or subclinical central or nephrogenic diabetes insipidus. These women have either decreased central secretory reserve or impaired renal responsiveness to vasopressin. In addition, women can experience diabetes insipidus de novo in pregnancy through the actions of placental vasopressinase, which causes accelerated degradation of vasopressin. This form of diabetes insipidus may be associated with increased complications of pregnancy, including preeclampsia. Management of central diabetes insipidus and transient diabetes insipidus of pregnancy can be achieved with 1-deamino-8-D-arginine vasopressin (desmopressin acetate) (DDAVP), a vasopressin analogue. Nephrogenic diabetes insipidus is typically resistant to both DDAVP and vasopressin and underlying causes should be addressed.
CONCLUSIONS: Increased awareness of diabetes insipidus in pregnancy may lead to early diagnosis and appropriate treatment that will reduce the risks of maternal and fetal morbidity. Overall, growing experience with DDAVP has shown that it is a safe and effective treatment for diabetes insipidus caused by a variety of factors.