Postnatal nutrition in extremely low birth weight infants and its impact on growth until the age of 6 years

Abstract

Aim: To examine the impact of postnatal nutrition on long-term growth in extremely low birth weight infants.

Method: Retrospective analysis of postnatal nutrition and observational study of growth in 52 ELBW infants until the age of six.

Results: Changes (Δ) in weight and length standard deviation scores (SDS) between birth to term correlated with protein intake (r(w) = 0.36; p = 0.009; r(L) = 0.35; p = 0.01), whereas ΔHC correlated with lipid intake (r(HC) = 0.38; p = 0.005). Analysis of various intervals (0-2, 3-5, 6-8 and 9-11 weeks) only showed significant impact on growth for energy (r = 0.3; p < 0.05) and lipids (r = 0.23; p < 0.05) at 6-8 weeks. No significant correlations were found between postnatal nutritional parameters and long-term growth. However, postnatal growth restraint was negatively associated with length SDS (r = -0.34; p = 0.015) and body mass index SDS (r = -0.34; p = 0.018) at the age of six. Infants with postnatal growth restraint (n = 25) caught up more in length (+1.78 SDS) than in weight (+0.43 SDS), whereas small for gestational age infants (n = 8) caught up more in weight (+1.35 SDS) than in length (+1.07 SDS). This difference remained significant at the age of six.

Conclusion: Although no direct association between postnatal nutrition and long-term growth was found, weight at discharge was a strong predictor for long-term growth.

Keywords: Extremely low birth weight; growth; nutrition; small for gestational age.