445 - Body Composition of Very Low Birth Weight Small for Gestational Age Premature Infants

Poster Number: 445
Publication Number: 445.335

Laura Lach, Medical University of South Carolina College of Medicine, Charleston, SC, United States; Katherine E. Chetta, Medical University of South Carolina College of Medicine, Charleston, SC, United States; Myla Ebeling, Northeast Ohio Medical University, Charleston, SC, United States; Lakshmi D. Katikaneni, MUSC Children's Hospital, Charleston, SC, United States

Background: Optimizing nutrition is important to prevent growth failure in the small for gestational age (SGA) and very low birth weight (VLBW, < 1500g) populations. Premature infant’s body composition differs compared to term infants, as they have higher body fat than term infants, and rapidly accumulate fat after birth. Few studies have reported the body composition of SGA ( < 10% birth weight for gestational age by Fenton curve) VLBW preterm infants using air body plethysmography (ABP).

Objective: The purpose of our study was to compare the percent fat of SGA and average for gestational age (AGA) infants without major co-morbidities in the VLBW population. We hypothesized that the percent fat of VLBW SGA infants would be lower than AGA infants before and after 60 weeks post menstrual age (PMA).

Design/Methods: From 2006-2012, 366 infants were admitted to the Medical University of South Carolina Level IV NICU and received an ADP (Pea Pod) assessment. A total of 92 VLBW AGA and SGA infants had no major co-morbidities (NEC, ROP Stage 3, IVH 3/4) and were included for analysis. Anthropometrics including length, weight, and head circumference percentiles (Fenton curve) were measured at birth and first ADP before 60 weeks PMA. Fifty-seven infants had two ADP evaluations obtained before and after 60 weeks PMA. Groups were analyzed using t-test (α = 0.05) and linear regression (SPSS V. 21).

Results: The average first ADP evaluation was 44 weeks PMA. There was no difference in weight gain, length or head circumference growth in the SGA versus AGA population from birth to the first ADP evaluation. At first ADP, SGA infants had lower body fat compared to AGA group (9.5% v 14.3%, P< 0.001). Of these 57 infants with two ADP evaluations, 14 (24.6%) were SGA and 43 (75.4%) were AGA. Before 60 weeks PMA, SGA infants had less percent fat than the AGA group (14.3% v 18.8%, P=0.004). However, after 60 weeks PMA, there was no difference between percent fat of the two groups (19.2% v 17.8%, P=0.4). Secondary outcomes included length of stay, multiples, and race. Longer length of stay in the NICU was associated with higher percent fat (p=0.013). Our study did not find a difference in fat percentage before and after 60 weeks PMA for race or multiples.Conclusion(s): Our data shows that the SGA VLBW group had lower body fat percent before 60 weeks PMA, however after 60 weeks PMA had similar body composition to the AGA group. We found no difference before and after 60 weeks PMA in body composition between singletons, multiples, or race. Future studies should investigate the variables affecting body fat accrual in SGA infants.
Percent Body Fat SGA v. AGA VLBW Infants