Effect of enteral zinc supplementation on growth and neurodevelopment of preterm infants: a systematic review and meta-analysis

OBJECTIVE: To evaluate effect of enteral zinc supplementation on growth and neurodevelopmental outcomes of preterm infants. STUDY DESIGN: A systematic review and meta-analysis of randomized-controlled trials (RCTs) examining growth and neurodevelopmental outcomes after zinc supplementation in preterm infants. RESULTS: Of eight RCTs involving 742 infants included, seven reported growth anthropometrics at 3-6 months corrected age (CA) and two reported neurodevelopmental outcomes at 6-12 months CA. Zinc supplementation was associated with increased weight z-score (weighted mean difference (WMD) = 0.50; 95% CI 0.23-0.76, heterogeneity I² = 89.1%; P < 0.01), length z-score (WMD = 1.12; 95% CI 0.63-1.61, heterogeneity I² = 96.0%; P < 0.01) and motor developmental score (WMD = 9.54; 95% CI 6.6-12.4 heterogeneity I² = 0%; P = 0.52). There was no effect on head circumference and total developmental score. Evidence is "moderate" certainty for weight and length and "very low" certainty for neurodevelopment.CONCLUSION: Zinc supplementation may enhance weight gain and linear growth in preterm infants. There is a lack of data about relationship between zinc supplementation and neurodevelopment.