Postnatal catch-up fat after late preterm birth

Abstract

Background: Late preterm birth accounts for 70% of preterm births. The aim of the study was to investigate the postnatal weight gain and weight gain composition changes in a cohort of late preterm infants. Methods: a total of 49 late preterm infants (mean birth weight 2,496 ± 330 g and gestational age 35.2 ± 0.7 wks) underwent growth and body composition assessment by an air displacement plethysmography system on the fifth day of life, at term, and at 1 and 3 mo of corrected age. The reference group was composed of 40 healthy, full-term, breast-fed infants. results: The late preterm infants showed a Δ fat mass gain between birth and term-corrected age equal to 182%. as compared with full-term infants, at term and 1 mo of corrected age mean weight (3,396 ± 390 vs. 3,074 ± 409 g and 4,521 ± 398 vs. 4,235 ± 673 g, respectively) and percentage of fat mass (16.1 ± 4.6 vs. 8.9 ± 2.9 and 22.6 ± 4.2 vs. 17.4 ± 4.0, respectively) were significantly higher in late preterm infants, whereas no difference among groups was found at 3 mo. conclusion: Rapid postnatal catch-up fat was found in these infants. Further studies are needed to investigate whether this short-term increase in fat mass may modulate the risk of chronic diseases or represent an adaptive mechanism to extrauterine life.

Early postnatal alteration of body composition in preterm and small-for-gestational-age infants: implications of catch-up fat

“…Ramel et al also investigated the body composition of preterm AGA infants born at 31.5 wk of gestation and term AGA infants at term-equivalent age (35), and observed markedly lower fat-free mass and higher adiposity in preterm infants. In addition, Giannì et al investigated changes in the body composition of late preterm AGA infants at gestational age 35.2 wk in a cohort study from birth (36). Late preterm AGA infants at birth exhibited a significantly lower birth weight and %BF (5.7%); however, at term-equivalent age, they were heavier and exhibited a great increase in fat mass so that they had higher %BF (16.1%) than term AGA infants have at birth (8.9%).…”

Is Fat Mass Accretion of Late Preterm Infants Associated with Insulin Resistance?

“…Late preterm infants exhibit a peculiar postnatal growth pattern with regard to weight gain composition; their body composition is characterized by a major accretion from birth to term in fat mass content, irrespectively of the percentile at birth, that leads to an increase in fat mass content, so that late preterm infants at term show a higher fat mass content than term infants at birth [3,4,5,6]. …”

Mid-arm circumference is a reliable method to estimate adiposity in preterm and term infants

“…It is unclear whether the increased preterm infant adiposity is due to an adaptation to the extrauterine environment and/or a combination of other causes (9). Theories regarding increased body fat in preterm compared with term infants include fat deposition related to illness, excessive calories administered by the health care team to ensure catch-up growth, maintenance of fluid balance and thermoregulation, or other stress after birth (9)(10)(11).…”

“…Theories regarding increased body fat in preterm compared with term infants include fat deposition related to illness, excessive calories administered by the health care team to ensure catch-up growth, maintenance of fluid balance and thermoregulation, or other stress after birth (9)(10)(11). For example, premature infants have increased circulating levels of cortisol compared with term cohorts (10,11).…”