Body composition of newborn twins: intrapair differences.
OBJECTIVE
To measure body composition in newborn twins and to test the hypothesis that differences in body weights between twins are reflected proportionally by their differences in various components of body composition.


METHODS
48 pairs of newborn twins delivered at a tertiary teaching hospital had dual energy x-ray absorptiometry (DXA) body composition measurement for bone mineral content (BMC), lean and fat mass (LM, FM). Data analyzed with regression and analysis of variance.


RESULTS
Body weight, BMC, LM and FM increased with increased gestational age (p < 0.001). The percent difference in BW between each twin pair was significantly correlated with percent difference in BMC, LM, and FM (p < 0.001). However, mean (+/- SD) percent difference in body weight (14.3+/-10.0%) was significantly lower (p < 0.001) than FM (26.0+/-15.0%) but was not significantly different from LM (13.4+/-9.0%) or BMC (15.9+/-11.6%).


CONCLUSIONS
In newborn twins, body weight and body composition varies with gestational age. For any twin pair, a difference in body weight was correlated with but not proportional to differences in individual components of body composition.
Koo
Belinda
B
Department of Pediatrics, Obstetrics and Gynecology, University of Tennessee, Memphis, USA.
Walters
Jocelyn
J
Hockman
Elaine
E
Koo
Winston
W
D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000000981:diagnostic imaging*; D000367:Age Factors; D000704:Analysis of Variance; D000886:Anthropometry; D001823:Body Composition / Q000502:physiology*; D015519:Bone Density / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D013851:Thinness / Q000000981:diagnostic imaging*; D014427:Twins