Maternal sociodemographic and health behaviours associated with adiposity in infants as measured by air displacement plethysmography.

Background: Identifying modifiable factors associated with body fat in infancy may improve health outcomes. Few studies have examined factors associated with percentage body fat calculated using air displacement plethysmography, a gold standard technique.

Aims: To investigate maternal sociodemographic and health behaviour characteristics associated with percentage body fat in offspring at birth.

Study Design: Observational cross-sectional study in which the body composition of term infants was measured by air displacement plethysmography during the hospital stay after birth.

Subjects: One-hundred-and-ninety-six women and their term (37-42 weeks) infants.

Outcome Measures: Associations between infant body composition and maternal sociodemographic and health characteristics.

Results: One-hundred-and-ninety-six women (41.8% primiparous) participated. Mean percentage body fat among infants (51.5% female) was 10.3 ± 3.7. Percentage body fat was significantly (p < 0.001) higher in infants born to women with an obese or overweight body mass index (BMI), when compared to infants born to women with a healthy BMI (12.1 ± 4.0, 11.1 ± 3.1, and 9.2 ± 3.7, respectively). A significant positive correlation (r = 0.294) was observed, with the percentage body fat of infants born to women with an overweight or obese BMI being 17.1% and 23.9% higher, respectively, than that of infants born to women with a healthy weight BMI. Percentage body fat was lower in infants born to primiparous women (p = 0.011) and women of low social class (p = 0.003).

Conclusions: Infants born to women with an overweight or obese pre-pregnancy BMI had significantly higher mean percentage body fat when compared to infants born to women with a healthy pre-pregnancy BMI. Research into approaches that promote a healthy BMI in advance of pregnancy is warranted.