title: Fetal and infant growth predict hip geometry at 6 y old: findings from the Southampton Women's Survey.
abstract: BACKGROUND
  We investigated relationships between early growth and proximal femoral geometry at age 6 y in a prospective population-based cohort, the Southampton Women's Survey.
  
  
  METHODS
  In 493 mother-offspring pairs, we assessed linear size using high-resolution ultrasound at 11, 19, and 34 wk gestation (femur length) and at birth and 1, 2, 3, 4, and 6 y (crown-heel length/height). SD scores were created and conditional regression modeling generated mutually independent growth variables. Children underwent hip dual-energy X-ray absorptiometry (DXA) at 6 y; hip structure analysis software yielded measures of geometry and strength.
  
  
  RESULTS
  There were strong associations between early linear growth and femoral neck section modulus (Z) at 6 y, with the strongest relationships observed for femur growth from 19 to 34 wk gestation (β = 0.26 cm(3)/SD, P < 0.0001), and for height growth from birth to 1 y (β = 0.25 cm(3)/SD, P < 0.0001) and 1 to 2 y (β = 0.33 cm(3)/SD, P < 0.0001), with progressively weaker relationships over years 3 (β = 0.23 cm(3)/SD, P = 0.0002) and 4 (β = 0.10 cm(3)/SD, P = 0.18).
  
  
  CONCLUSIONS
  These results demonstrate that growth before age 3 y predicts proximal femoral geometry at 6 y old. These data suggest critical periods in which there is capacity for long-term influence on the later skeletal growth trajectory.
authors.affiliation: 1] Medical Research Council Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK [2] National Institute for Health Research Southampton Biomedical Research Centre, University of Southampton, and University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Southampton, UK.
authors.forename: Nicholas C
authors.initials: NC
authors.lastname: Harvey
authors.forename: Zoe A
authors.initials: ZA
authors.lastname: Cole
authors.forename: Sarah R
authors.initials: SR
authors.lastname: Crozier
authors.forename: Georgia
authors.initials: G
authors.lastname: Ntani
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Mahon
authors.forename: Sian M
authors.initials: SM
authors.lastname: Robinson
authors.forename: Hazel M
authors.initials: HM
authors.lastname: Inskip
authors.forename: Keith M
authors.initials: KM
authors.lastname: Godfrey
authors.forename: Elaine M
authors.initials: EM
authors.lastname: Dennison
authors.forename: Cyrus
authors.initials: C
authors.lastname: Cooper
mesh_terms: D015502:Absorptiometry, Photon; D000367:Age Factors; D002648:Child; D015331:Cohort Studies; D005269:Femur / Q000033:anatomy & histology* / Q000254:growth & development; D047109:Fetal Development / Q000502:physiology*; D005333:Fetus; D006615:Hip / Q000033:anatomy & histology* / Q000254:growth & development; D006801:Humans; D007231:Infant, Newborn / Q000254:growth & development*; D011446:Prospective Studies; D012044:Regression Analysis