Zinc concentration in preterm newborns at term age, a prospective observational study

OBJECTIVES: To determine zinc concentrations and associated factors in a population of preterm newborns at term age. DESIGN: This analytical, descriptive, observational and prospective study was conducted in the neonatal unit of a tertiary hospital. Preterm newborn between gestational weeks 24 and 34 were included in the study. The patients were recruited close to the date of birth. Their clinical histories were collected, and the serum zinc concentrations (SZCs) at gestational weeks 37–41 were measured. This study aimed to measure SZC in a population of preterm newborns at term age, and analyse the anthropometric, clinical and nutritional parameters associated with a decrease in SZC. RESULTS: Overall, 83 preterm subjects were evaluated, including 44 (53%) female infants and 39 (47%) male infants. The median period of gestation was 31 (IQ25–IQ75: 29–33) weeks, and the mean weight at birth was 1.523±0.535 kg. The median SZC at term was 4.4 (IQ25–IQ75: 2.6–6.9) µmol/L. There were some variables associated with zinc concentrations like bronchopulmonary dysplasia (BPD), weight at birth, z-score of length at discharge, being small for gestational age and treatment with recombinant human erythropoietin, although the unique variable that was independent of the other variables in the multivariate analysis (p 0.01) was BPD. Preterm newborn with BPD had lower SZC at term age than those without (2.7 vs 4.9 µmol/L, p 0.005). CONCLUSIONS: Zinc concentrations in this preterm population were low. BPD was significantly and negatively correlated with zinc concentrations. CLINICAL TRIAL REGISTRATION: NCT03532555.