Gestational diabetes insipidus: a case report

L.T. van Hulsteijn, M. van Buren, H. van Houten

Woensdag 20 april 2016

15:20 - 15:30u in Auditorium 2

Categorie├źn: Parallelsessie

Parallel sessie: Parallelsessie 2: Case reports/research

Case: A 38-year old woman, 38 weeks pregnant, presented at the outpatient clinic with complaints of polyuria and polydipsia. It concerned her 4th pregnancy. Her medical history was unremarkable and she used no medication. A general physical examination revealed no irregularities. Glucose, renal and electrolyte profiles were within normal ranges. Plasma osmolality was 289 mosmol/kg. The volume of a 24-hour urine collection was 5663 ml with an osmolality of 152 mosmol/kg, which raised the suspicion of diabetes insipidus (DI). There were no signs of central DI. Because of pregnancy, a water deprivation test was not executed. We concluded our patient had gestational DI. She was treated with desmopressin nasally. The complaints of polyuria and polydipsia resolved and urine osmolality returned to normal levels. After labour, desmopressin was successfully stopped.

Discussion: Gestational DI is a transient form of DI and usually occurs in the 3th trimester of pregnancy. It is caused by excessive placental production of vasopressinase, which degradates vasopressin (ADH) via the N-terminal amino acids of the vasopressin molecule. Excessive production is associated with a larger placenta, e.g. in women carrying multiple or twin pregnancies. Because desmopressin is already deaminated at the N-terminal, it is resistant to degradation by vasopressinase and therefore can be used in the treatment of gestational DI. After labour, circulating levels of vasopressin return to normal and treatment can be terminated.