Rapid Recovery of Fat Mass in Small for Gestational Age Preterm Infants after Term

Abstract

BackgroundPreterm small for gestational age (SGA) infants may be at risk for increased adiposity, especially when experiencing rapid postnatal weight gain. Data on the dynamic features of body weight and fat mass (FM) gain that occurs early in life is scarce. We investigated the postnatal weight and FM gain during the first five months after term in a cohort of preterm infants.Methodology/Principal FindingsChanges in growth parameters and FM were prospectively monitored in 195 infants with birth weight ≤1500 g. The infants were categorized as born adequate for gestational age (AGA) without growth retardation at term (GR−), born AGA with growth retardation at term (GR+), born SGA. Weight and FM were assessed by an air displacement plethysmography system. At five months, weight z-score was comparable between the AGA (GR+) and the AGA (GR−), whereas the SGA showed a significantly lower weight.The mean weight (g) differences (95% CI) between SGA and AGA (GR−) and between SGA and AGA (GR+) infants at 5 months were −613 (−1215; −12) and −573 (−1227; −79), respectively. At term, the AGA (GR+) and the SGA groups showed a significantly lower FM than the AGA (GR−) group. In the first three months, change in FM was comparable between the AGA (GR+) and the SGA groups and significantly higher than that of the AGA (GR−) group.The mean difference (95% CI) in FM change between SGA and AGA (GR−) and between AGA (GR+) and AGA (GR−) from term to 3 months were 38.6 (12; 65); and 37.7 (10; 65). At three months, the FM was similar in all groups.ConclusionsOur data suggests that fetal growth pattern influences the potential to rapidly correct anthropometry whereas the restoration of fat stores takes place irrespective of birth weight. The metabolic consequences of these findings need to be elucidated.

Evaluation of air-displacement plethysmography for body composition assessment in preterm infants

“…As the aforementioned results indicate, precision of the ADP system was excellent, with a mean difference of 0.15% between repeated ADP tests. Similarly, there was good agreement between ADP and the H 2 18 O dilution method, as indicated by a mean difference of 0.32% FM and 95% limit of agreement at −3.4 and 2.76 %FM. In addition, regression Articles Air-displacement plethysmography analyses with the two methods provided a low SEE value of 1.65% and a moderate R 2 value of 0.62.…”

“…The differences between the values obtained with the ADP system and the H 2 18 O dilution measurement were not a function of the mean values for the two methods (P = 0.16), indicating no systematic bias as body fatness increased. The 95% limits of agreement were at -3.4 and 2.76 %FM.…”

“…t here has been an increasing focus on nutrition and its impact on the quality of growth in preterm infants (1)(2)(3). Indeed, body composition, in terms of fat mass (FM), may contribute to the future risk of disease (4).…”

Postnatal catch-up fat after late preterm birth

“…It has been found that extremely preterm infants, including those born small for gestational age, show a major deposition of fat mass in early postnatal life so that they show an increased adiposity at term-corrected age (7,14). However, within the first 3-4 mo of corrected age, extremely preterm infants succeed in achieving fat mass values similar to those of full-term infants (9,15).…”

“…Indeed, extremely preterm infants, assessed at term-corrected age, have been found to be at increased risk for developing increased and/or aberrant adiposity, which is a known risk marker for cardiovascular disease (7,8). However, it has been reported that preterm infants born appropriate for gestational age succeed in recovering growth and fat mass within the third month of corrected age (9). To our knowledge, data regarding the early dynamic features of growth and body composition changes of late preterm infants are scarce.…”