Effects of standardized parenteral nutrition on electrolyte balance: an observational study in preterm neonates

Preterm neonates require parenteral nutrition (PN) during the first days of life due to gastrointestinal immaturity. Two main formulations are available: individualized parenteral nutrition (IPN) and standardized parenteral nutrition (SPN). The literature remains inconclusive regarding their comparative safety, particularly concerning electrolyte balance. The aim of this cohort study was to evaluate whether an association exists between different PN formulations and the development of electrolyte disturbances in preterm infants.

This single-center retrospective observational cohort study included all neonates with gestational age ≤34 weeks and/or birth weight ≤1,500 g admitted to the NICU of Policlinico Umberto I, Sapienza University of Rome, who received PN for at least 3 days between January 2015 and December 2024. Cohort A (n = 362) received IPN and Cohort B (n = 33) received SPN (Numeta^® G13%E). Electrolyte disturbances, nutritional intakes, and morbidities were compared. Binary logistic regression was used to identify independent risk factors.

No significant differences in baseline clinical characteristics were observed between groups. Use of SPN was associated with significantly lower intakes of sodium and calcium during the first week of life. In multivariable analysis, SPN was independently associated with hyponatremia (OR 38.9, p < 0.001), hyperkalemia (OR 2.5, p = 0.021), hypocalcemia (OR 4.1, p < 0.001), and hyperphosphatemia (OR 7.1, p < 0.001).

In this study, standardized parenteral nutrition was associated with a significantly higher risk of electrolyte and mineral imbalances compared with individualized formulations. Where SPN is used, supplementation strategies should be considered to prevent complications.