Diabetes insipidus in pregnancy: how to advice the patient?

Diabetes insipidus, characterized by polyuria and polydipsia, is a rare disease during pregnancy. Nevertheless, its recognition is important to avoid complications due to dehydration and hypernatremia. Its manifestation during pregnancy ranges from exacerbation of pre-existing central or nephrogenic diabetes insipidus to transient pregnancy-induced diabetes insipidus due to the increased metabolism of the antidiuretic hormone vasopressin (AVP) by the placental vasopressinase. Diagnosis can be challenging, as urinary frequency is common during pregnancy and primary polydipsia also needs to be excluded. Also, the standard water deprivation test is not recommended during pregnancy due to the increased risk of complications. Treatment depends upon the final diagnosis, with desmopressin (DDAVP) being the medication of choice in AVP-deficient diabetes insipidus, whereas nephrogenic diabetes insipidus requires treatment of the underlying disease and supportive measures.