Presented at the Neonatal Society 2015 Summer Meeting.
Chan S1, Johnson MJ2,3, Leaf AA2, Vollmer B4
1 Faculty of Medicine, University of Southampton
2 NIHR Nutrition Biomedical Research Centre Southampton, University Hospital Southampton NHS Foundation Trust and University of Southampton
3 Department of Neonatal Medicine, University Hospital Southampton NHS Foundation Trust
4 Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton
Background: Infants born very preterm are at risk of adverse neurodevelopmental outcomes, and this has been associated to some extent with growth and nutrition during the neonatal period. The effects of higher nutritional intakes on neurodevelopmental outcomes is unclear. We conducted a systematic review in order to examine the effects of either increased parenteral nutrition (PN), enteral nutrition (EN) or both during the neonatal period on neurodevelopmental outcomes in infants born at <32 weeks of gestation or weighing <1501g at birth.
Methods: Medline, Embase, CINAHL, HMIC and “Web of science” were searched electronically, with selective citation and reference searching. Included studies had to have provided increased nutrition during the neonatal period and carried out neurodevelopmental or cognitive assessment at toddler age or later childhood. Details on nutritional interventions and neurodevelopmental outcomes were extracted. Meta-analysis and meta-regressions were conducted where appropriate.
Results: Fifteen trials and 4182 infants (1760 = intervention group, 2422 = control group) were included. Six trials examined the effect of increased PN, seven trials examined the effect of EN and two trials looked at both. Meta-analysis was carried out on the most consistently reported outcomes, including the subscales of the Bayley Scales of Infant Development II (BSIDII) at 12-18 months and 24 months corrected gestational age (CGA). Meta-analysis of the PN trials demonstrated a significant decrease in the Mental Developmental Index by 3.99 points (-7.69, -0.29; p=0.03) in the intervention group compared to the control group at 24 months CGA. Results at 12-18 months revealed no significant effect on neurodevelopmental outcomes from enhanced EN or PN. Overall, an increase in nutrition during the neonatal period was not shown to cause significant harms.
Conclusion: The effects of early enteral nutrition on neurodevelopmental outcomes in infants born very preterm and/or with very low birth weight remains unclear, but this review showed that increased early PN may cause unfavourable neurodevelopmental outcomes. While the meta-analysis from this systematic review was limited by the heterogeneous interventions and outcome measures across the trials, such findings require confirmation from further research. Future studies should focus on including standardised nutritional interventions and using a set of agreed and standardised neurodevelopmental outcome measures to provide stronger and more conclusive evidence.
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