ACTA ENDOCRINOLOGICA (BUC)

Context. Diabetes insipidus (DI) is rare in the neonatal period but of great importance due to increased renal risk and mental retardation despite treatment. Objective. This report describes the case of a patient with congenital nephrogenic diabetes insipidus (NDI). Detection of this pathology during the neonatal period, especially in premature newborns, is difficult because of the electrolyte variations that occur as a result of the immature kidney function. Subjects and methods. The subject was a preterm infant with very low birth weight (VLBW) and persistent hypernatremic hyperosmolarity that developed polyuria and polydipsia in the first weeks of life. Results. Taking into account blood and urine laboratory tests, vasopressin levels, as well as family history, the infant was diagnosed with congenital NDI. Early treatment allowed a good development, proving that the prevention of long-term complications is possible through multidisciplinary care and frequent monitoring. The particularity of this case was the presence of persistently elevated presepsin levels. This association prompted the investigation into underlying renal hypernatremia. Conclusions. NDI is a rare condition and the onset in the neonatal period is a sign of severity and hereditary causality. Early diagnosis, symptomatic treatment and multidisciplinary monitoring may decrease the risk of longterm complications.