Prenatal presentation of transient central diabetes insipidus.

Introduction: Nephrogenic diabetes insipidus (DI) in the foetus has been described as a rare presentation of severe polyhydramnios.

Discussion: We report a case of foetal central DI, characterised by severe polyhydramnios. Significant polyuria was noted at birth. Serum AVP level was un-measurable (<0.5 pg/ml). A dramatic response to intravenous dDAVP (desmopressin) was noted confirming central DI. Further investigations did not reveal a recognised cause for central or nephrogenic DI. The infant thrived well on a small dose of oral desmopressin until the age of 12 months. At 13 months, a water deprivation test revealed a normal ability to concentrate urine without desmopressin, and subsequently, the infant has thrived without further treatment. The transient nature of the central DI remains obscure but could be explained by a maturational delay in the tissues involved in AVP synthesis or release, during intrauterine life and infancy.

Conclusion: Both nephrogenic and central DI should be considered as a cause of severe polyhydramnios. This may help to guide prompt intensive management and investigation, with attention to vascular access, central venous pressure, urine output monitoring and replacement.