title: Fetal and postnatal growth and body composition at 6 months of age.
abstract: OBJECTIVE
  The objectives of the study was to examine which parental, fetal, and postnatal characteristics are associated with fat and lean mass at the age of 6 months and examine the effect of growth (catch-down, catch-up) in fetal life and early infancy on fat and lean mass.
  
  
  METHODS
  This study was embedded in the Generation R Study, a prospective cohort study from early fetal life onward. Body composition was measured by dual-energy X-ray absorptiometry in 252 infants at 6 months. Parental, fetal, and postnatal data were collected by physical and fetal ultrasound examinations and questionnaires.
  
  
  RESULTS
  Children with fetal catch-up in weight (gain in weight sd score >0.67) in the second trimester tended to have a higher fat mass percentage [FM(%)] at 6 months of age, whereas children with fetal catch-down in weight had a lower FM(%) compared with nonchangers. In the third trimester, both catch-up and catch-down in weight were associated with an increase in FM(%) at 6 months. Children with catch-down in the third trimester had a greater risk for postnatal catch-up in weight greater than 0.67 sd score. Birth weight and weight at 6 wk were positively associated with fat mass at 6 months. Postnatal catch-up in weight within 6 wk after birth had the highest association with total and truncal FM(%) at 6 months. Total and truncal FM were higher in girls.
  
  
  CONCLUSIONS
  Catch-down in weight in the third trimester was strongly associated with postnatal catch-up within 6 wk after birth, and both were associated with an increase in fat mass at the age of 6 months. Our study shows that fetal as well as postnatal growth patterns are associated with body composition in early childhood.
authors.affiliation: The Generation R Study Group (AE006), Department of Pediatrics, Erasmus Medical Center, P.O. Box 2040, Rotterdam 3000 CA, The Netherlands. l.ay@erasmusmc.nl
authors.forename: Lamise
authors.initials: L
authors.lastname: Ay
authors.forename: Vera A A
authors.initials: VA
authors.lastname: Van Houten
authors.forename: Eric A P
authors.initials: EA
authors.lastname: Steegers
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.forename: Jacqueline C M
authors.initials: JC
authors.lastname: Witteman
authors.forename: Vincent W V
authors.initials: VW
authors.lastname: Jaddoe
authors.forename: Anita C S
authors.initials: AC
authors.lastname: Hokken-Koelega
mesh_terms: D000367:Age Factors; D001724:Birth Weight / Q000502:physiology; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D001942:Breast Feeding / Q000453:epidemiology; D002657:Child Development / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D047109:Fetal Development / Q000502:physiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011263:Pregnancy Trimester, Third / Q000502:physiology