Preterm birth and body composition at term equivalent age: a systematic review and meta-analysis.
OBJECTIVE
Infants born preterm are significantly lighter and shorter on reaching term equivalent age (TEA) than are those born at term, but the relation with body composition is less clear. We conducted a systematic review to assess the body composition at TEA of infants born preterm.


METHODS
The databases MEDLINE, Embase, CINAHL, HMIC, "Web of Science," and "CSA Conference Papers Index" were searched between 1947 and June 2011, with selective citation and reference searching. Included studies had to have directly compared measures of body composition at TEA in preterm infants and infants born full-term. Data on body composition, anthropometry, and birth details were extracted from each article.


RESULTS
Eight studies (733 infants) fulfilled the inclusion criteria. Mean gestational age and weight at birth were 30.0 weeks and 1.18 kg in the preterm group and 39.6 weeks and 3.41 kg in the term group, respectively. Meta-analysis showed that the preterm infants had a greater percentage total body fat at TEA than those born full-term (mean difference, 3%; P = .03), less fat mass (mean difference, 50 g; P = .03), and much less fat-free mass (mean difference, 460 g; P < .0001).


CONCLUSIONS
The body composition at TEA of infants born preterm is different than that of infants born at term. Preterm infants have less lean tissue but more similar fat mass. There is a need to determine whether improved nutritional management can enhance lean tissue acquisition, which indicates a need for measures of body composition in addition to routine anthropometry.
Southampton NIHR Nutrition, Diet and Lifestyle Biomedical Research Unit, Princess Anne Hospital, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom. m.johnson@soton.ac.uk
Mark J
MJ
Johnson
Stephen A
SA
Wootton
Alison A
AA
Leaf
Alan A
AA
Jackson
D001724:Birth Weight; D001823:Body Composition; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D011247:Pregnancy; D047929:Term Birth