Oral sodium supplementation on growth and hypertension in preterm infants: an observational cohort study

To evaluate the association between enteral sodium supplementation on growth and hypertension (HTN) in preterm infants.

A retrospective cohort study of infants born between 22–32 weeks and weighing 450–1500 grams (N = 821). Enteral sodium supplementation amounts, systolic blood pressures (SBP), weight gain, and other infant and maternal risk factors for HTN were electronically extracted.

Infants receiving sodium supplementation were smaller and less mature. Sodium supplementation improved serum sodium levels, weight gain, and head circumference growth without causing hypernatremia. There was no correlation between urine and serum sodium or urine sodium and weight gain. Although infants receiving sodium had higher average SBP and rates of HTN, analysis demonstrated sodium supplementation did not increase odds of hypertension (OR_ADJ 1.02;0.64–1.64). Postnatal steroids were associated with HTN.

In preterm infants with poor weight gain, enteral sodium supplementation improved growth without increasing hypertension or hypernatremia.