Journal Club: Early sodium supplementation helps preemies grow

Sodium supplementation in very preterm infants improves in-hospital weight gain and linear growth, a randomized controlled trial showed. The trial, conducted in India, involved preterm babies with a gestational age between 25 weeks and 30 weeks + 6 days who received at least 100 mL/kg/d of breast milk by 10 days of life and had serum sodium of <145 mmol/L. Half of the 104 neonates received 4 mEq/kg/day of sodium as 1.6 mL/kg/day of 15% saline. The other half, the control group, were given 1.6 mL/kg/day of 0.45% saline. Infants in both groups received their respective doses mixed with milk whenever they were fed. Investigators recalculated the babies’ doses every 3 days in line with their working weight. The supplements were administered up to 34 weeks of postmenstrual age.

The mean weight velocity of babies in the intervention group was significantly higher than that of the babies in the control group, a mean difference of 3.65 gm/kg/d. This difference between the 2 groups was most apparent from week 3 onwards. In addition, mean weekly length velocity was significantly higher in the intervention group than in the control group. Also, whereas 16 babies in the intervention group required correction for hyponatremia, 34 babies in the control group needed this correction. Finally, extrauterine growth restriction was observed in 27 infants in the intervention group compared with 36 in the control group, although this difference was not statistically significant. In addition, a subgroup analysis in extremely preterm neonates found that compared with the control group, babies in the intervention group had significantly higher mean growth velocity, took less time for sodium correction among those who developed hyponatremia, and regained birth weight earlier.

Investigators also noted that sodium supplementation was not associated with food intolerance or necrotizing enterocolitis.

THOUGHTS FROM DR. FARBER

I wouldn’t be ready to do this routinely based on this 1 study, but if you have a healthy, very premature baby who is not growing well, sodium supplementation would be worth considering.

Reference

Amiti A, Balakrishnan U, Devi U, Amboiram P, Salahudeen AG. Effect of early sodium supplementation on weight gain of very preterm infants: a randomized controlled trial. BMJ Paediatr Open. 2025;13;9(1):e003444.doi:10:1136/bmjpo-2025-003444.