Early postnatal growth and neurodevelopment in children born moderately preterm or small for gestational age at term: A systematic review

BACKGROUND: Clinicians' interest in the long-term effects of early postnatal growth (EPG) is growing. There is compelling evidence linking rapid EPG with later cardiovascular risk, but its neurodevelopmental benefits still remain hypothetical in individuals born moderately preterm (MP) or small for gestational at term (SGAT). METHODS: The objective was to perform a systematic review of the relationship between EPG before age 3 years and neurodevelopmental outcome for individuals born MP (32-36 weeks' gestational age) or SGAT. Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, 3 independent investigators searched for articles published on this topic in the Web of Science, EMBASE and PubMed from database inception to July 1, 2017. A detailed quality scale was used to evaluate articles. RESULTS: We selected 19 articles relying on 12 distinct study populations; 7 articles from 3 study populations were considered at moderate or high quality. The lack of standardisation of growth analysis methods prevented performing a meta-analysis. Overall, EPG was positively associated with neurodevelopmental outcome, especially Intelligence Quotient (IQ) when available. In this relationship, the first 6 months of life might be a critical period. Analysis of the few articles investigating the shape of the relationships revealed a non-linear association, with a plateau for IQ with higher weight gain, which suggests a possible ceiling effect. CONCLUSIONS: A positive association was generally found between EPG and neurodevelopmental outcome for individuals born MP or SGAT. Strategies for future epidemiological studies are suggested to improve the characterisation of this relationship.