Body Composition of Preterm Infants following Rapid Transition to Enteral Feeding.

OBJECTIVE

This study aimed to evaluate body composition at the time of hospital discharge in very preterm infants following rapid transition to full enteral feeding.

STUDY

DESIGN

We conducted a prospective, observational, cross-sectional study and included 105 preterm infants <32 gestational age or birth weight <1,500 g, born between April 2015 and December 2020, following rapid transition to full enteral feeding (≥140 mL/kg/day). Fat mass/total body mass (BF%) and fat-free mass (FFM) were measured at the time of hospital discharge using air displacement plethysmography.

RESULTS

Median and interquartile range (Q1-Q3) of gestational age at birth (GA) was 27.3 (26.1-28.7) weeks and birth weight 845 (687-990) g. Time to reach full enteral feeding was 5 (5-7) days. At 37.6 weeks (36.1-39.0) postmenstrual age (PMA), BF% was 17.0% (14.9-19.8) and FFM 2,161 g (1,966-2,432). BF% was not associated with GA, and not different between small and appropriate for gestational age infants. FFM was significantly lower in infants born small for gestational age.

CONCLUSIONS

Following rapid transition to full enteral feeding, FFM and BF% at discharge were similar to other preterm populations. BF% and FFM were not associated with GA at birth but with PMA at measurement. FFM was lower and BF% higher compared to term infants at birth, suggesting diminished parenchymal growth in preterm infants. Continued monitoring of body composition, metabolic health, and neurological development is needed to study long-term effects.