Jeffrey Segar, MD, highlights sodium supplementation to support infant weight gain

In a Contemporary Pediatrics interview, Jeffrey L. Segar, MD, neonatology specialist at the Medical College of Wisconsin, discussed research examining the impact of sodium supplementation on weight gain in very preterm infants and how targeted approaches may improve early growth outcomes in the neonatal intensive care unit (NICU).

Segar explained that his work in this area spans more than a decade and began with concerns that many extremely preterm infants may not be receiving sufficient sodium to support optimal growth. In an early study, his team used urine sodium concentrations to identify infants at risk for sodium depletion.

Infants found to have low urine sodium levels were given supplemental sodium, and their growth outcomes were compared with those of historical controls. The results showed that infants who received supplementation demonstrated improved growth, including greater weight gain, compared with infants managed under standard practices.

Building on these findings, Segar and colleagues conducted a randomized clinical trial using a similar urine sodium–based algorithm. Once again, infants who received sodium amounts above what is typically provided in current NICU practice experienced improved weight gain over the first several weeks to months of life. These results reinforced the idea that sodium intake may be a limiting factor for growth in very preterm infants, particularly those born before 29 to 30 weeks’ gestation.

Segar emphasized the clinical importance of supporting adequate weight gain in this population. Improved early growth in preterm infants has been consistently associated with better neurodevelopmental outcomes later in life. Although the study did not directly assess neurodevelopment, Segar noted that achieving more appropriate growth trajectories may help support brain development and potentially reduce the risk of other morbidities linked to preterm birth.

The interview also highlighted how urine sodium measurements can be used pragmatically in clinical care. One key lesson from the trial was that a substantial proportion of infants randomized to the algorithm group were sodium depleted, suggesting that standard sodium provision in the NICU may be insufficient for many extremely preterm infants.

Segar suggested that neonatologists may need to reconsider baseline sodium supplementation practices. While he does not advocate routine urine sodium testing for all preterm infants, he noted that measuring urine sodium can be particularly useful when an infant is not growing as expected despite adequate caloric and protein intake. In such cases, low urine sodium levels may justify additional dietary sodium.

Finally, Segar underscored that important questions remain unanswered, particularly regarding the optimal amount of sodium for preterm infants across different gestational and postnatal ages. Ongoing and future research, he said, is needed to inform more precise and evidence-based guidelines for sodium supplementation in neonatal care.

No relevant disclosures.

Reference

Liberio BM, Sokol GM, Takow H, et al. Sodium supplementation algorithm to promote growth in preterm infants: randomized clinical trial. Pediatrics Open Science. 2025. doi:10.1542/pedsos.2025-001089