Gender- and gestational age-specific body fat percentage at birth

Pediatrics. 2011 Sep;128(3):e645-51. doi: 10.1542/peds.2010-3856. Epub 2011 Aug 8.


Background: There is increasing evidence that in utero growth has both immediate and far-reaching influence on health. Birth weight and length are used as surrogate measures of in utero growth. However, these measures poorly reflect neonatal adiposity. Air-displacement plethysmography has been validated for the measurement of body fat in the neonatal population.

Objective: The goal of this study was to show the normal reference values of percentage body fat (%BF) in infants during the first 4 days of life.

Methods: As part of a large population-based birth cohort study, fat mass, fat-free mass, and %BF were measured within the first 4 days of life using air-displacement plethsymography. Infants were grouped into gestational age and gender categories.

Results: Of the 786 enrolled infants, fat mass, fat-free mass, and %BF were measured in 743 (94.5%) infants within the first 4 days of life. %BF increased significantly with gestational age. Mean (SD) %BF at 36 to 37⁶/⁷ weeks' gestation was 8.9% (3.5%); at 38 to 39 weeks' gestation, 10.3% (4%); and at 40 to 41⁶/⁷ weeks' gestation, 11.2% (4.3%) (P < .001). Female infants had significantly increased mean (SD) %BF at 38 to 39⁶/⁷ (11.1% [3.9%] vs 9.8% [3.9%]; P = .012) and at 40 to 41⁶/⁷ (12.5% [4.4%] vs 10% [3.9%]; P < .001) weeks' gestation compared with male infants. Gender- and gestational age-specific centiles were calculated, and a normative table was generated for reference.

Conclusion: %BF at birth is influenced by gestational age and gender. We generated accurate %BF centiles from a large population-based cohort.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue*
  • Adiposity*
  • Body Composition*
  • Body Mass Index
  • Female
  • Gestational Age*
  • Humans
  • Male
  • Plethysmography
  • Sex Factors