Exacerbation of pre-existing diabetes insipidus during pregnancy, mechanisms and management

During pregnancy, physiological changes in osmotic homeostasis cause water retention. If excessive, this can cause gestational diabetes insipidus (DI), particularly in patients with already impaired vasopressin secretion. We present the case of a 34-year-old patient with pre-existing hypopituitarism who experienced a transient exacerbation of her DI during a twin pregnancy. In contrast to typical gestational DI, polyuria and polydipsia occurred during the first trimester and remained stable thereafter. This case highlights a challenging clinical entity of which pathophysiology, diagnostic approach and treatment will be discussed.