Enhanced nutrient supply to very low birth weight infants is associated with improved white matter maturation and head growth.
BACKGROUND
Extrauterine growth restriction is common among very low birth weight infants (VLBW, BW <1,500 g). Optimal postnatal nutrient supply is essential to limit growth restriction and ensure adequate growth and neurodevelopment.


OBJECTIVE
We compared an enhanced postnatal nutrient supply to a standard supply and evaluated the effects on growth velocity, head circumference growth and cerebral maturation - the latter by magnetic resonance diffusion tensor imaging (DTI). We hypothesized increased growth velocity, head circumference growth and decreased mean diffusivity (MD) in cerebral white matter (WM) areas, suggesting improved cerebral maturation among infants on the enhanced nutrient supply.


METHODS
In this randomized controlled trial, infants on the enhanced nutrient supply received increased amounts of energy, protein, fat, essential fatty acids and vitamin A until discharge. DTI was performed close to term equivalent age. Outcomes were growth velocity, head circumference growth and WM mean diffusivity.


RESULTS
Among the 50 included infants, 14 in the intervention group and 11 controls underwent a successful DTI. Infants on the enhanced diet achieved improved growth velocity (16.5 vs. 13.8 g/kg/day, p = 0.01) and increased head circumference (Δz score: 0.24 vs. -0.12, p = 0.15). A significantly lower MD was seen in a large WM area such as the superior longitudinal fasciculi (1.19 × 10(-3) vs. 1.24 × 10(-3) mm(2)/s, p = 0.04, adjusted for age when scanned).


CONCLUSIONS
Enhanced nutrient supply to VLBW infants is associated with improved growth velocity, increased head circumference growth and decreased regional WM mean diffusivity, suggesting improved maturation of cerebral connective tracts.
Department of Neonatal Intensive Care, Women and Children's Division, Oslo University Hospital Rikshospitalet, Oslo, Norway.
Kenneth
K
Strømmen
Elin W
EW
Blakstad
Sissel J
SJ
Moltu
Astrid N
AN
Almaas
Ane C
AC
Westerberg
Inge K
IK
Amlien
Arild E
AE
Rønnestad
Britt
B
Nakstad
Christian A
CA
Drevon
Atle
A
Bjørnerud
Frederic
F
Courivaud
Per K
PK
Hol
Marit B
MB
Veierød
Anders M
AM
Fjell
Kristine B
KB
Walhovd
Per O
PO
Iversen
D002508:Cephalometry / Q000379:methods; D002657:Child Development / Q000502:physiology; D005260:Female; D006257:Head / Q000254:growth & development*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000254:growth & development; D019102:Infant, Very Low Birth Weight / Q000254:growth & development; D008279:Magnetic Resonance Imaging; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D018529:Nutritional Support / Q000379:methods*; D016896:Treatment Outcome; D066127:White Matter / Q000254:growth & development*