Prevalence and Risk Factors for Hyponatremia in Preterm Infants

Hyponatremia is the result of a negative sodium balance caused by inadequate salt intake or excessive salt loss due to immature renal or intestinal function in preterm infants.

The aim of our study was to define the incidence of and factors affecting its development in preterm newborns.

This was a retrospective cohort analysis of 126 preterm infants born before 36 weeks of gestation between June 2016 and July 2018 at Neonatal Intensive Care Unit of Hue Central Hospital, Vietnam. Hyponatremia was defined as a sodium level ≤ 132 mEq/L or 133-135 mEq/L with oral sodium supplementation. We used the serum sodium level to define hyponatremia.

There were 37 infants who had hyponatremia, accounting for 29.4% of the infants enrolled in the study. Alower gestational age, the presence of respiratory distress syndrome, the use of furosemide, and feeding with breast milk were significant risk factors for hyponatremia in preterm newborns.

Hyponatremia occurred at a relatively high frequency. This result exemplifies the importance of serum sodium monitoring and supplementation for the correction of hyponatremia.