Background: There is increasing evidence that body composition in early life has both immediate and long-term influence on health. Air-displacement plethysmography creates the opportunity to study the effect of prenatal and early postnatal factors on neonatal body composition. Prenatal maternal factors, such as pre-pregnancy BMI and gestational weight gain, might also influence neonatal body composition.
Objective and Hypotheses: We hypothesized that newborns with a similar birth weight have different fat mass percentages (FM%), related with gender, gestational age and the pre-pregnancy BMI and gestational weight gain of the mother.
Method: The study population comprised 200 healthy newborns, with a gestational age between 35.2 and 42 weeks, born in Erasmus MC Sophia Childrens Hospital. Within 3 days after birth, weight, crown-to-heel length, head circumference and whole-body composition were assessed using air-displacement plethysmography (PEA POD, Infant Body Composition System, COSMED). Maternal data, i.e. weight before and at end of pregnancy, height and parity were obtained from medical records.
Results: The newborns showed a large range in FM% (1.4-19.9%). There was a large variation in FM%, even in children with the same weight. Weight was strongly related with fat mass in kg (r=0.70 P<0.001). Mean fat mass in kg increased with gestational age (r=0.22, P=0.001), but FM% did not. The pre-pregnancy BMI of the mother correlated with the FM% of the newborn (r=0.14, P=0.04), but gestational weight gain of the mother did not correlate with the FM% of the newborn.
Conclusion: Our study has generated accurate FM% and fat mass reference data in a large population of healthy newborns. Newborn infants showed a large variation in FM%, which was associated with mothers pre-pregnancy BMI and surprisingly not with the weight gain during pregnancy.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology