title: Different indices of fetal growth predict bone size and volumetric density at 4 years of age.
abstract: We have demonstrated previously that higher birth weight is associated with greater peak and later-life bone mineral content and that maternal body build, diet, and lifestyle influence prenatal bone mineral accrual. To examine prenatal influences on bone health further, we related ultrasound measures of fetal growth to childhood bone size and density. We derived Z-scores for fetal femur length and abdominal circumference and conditional growth velocity from 19 to 34 weeks' gestation from ultrasound measurements in participants in the Southampton Women's Survey. A total of 380 of the offspring underwent dual-energy X-ray absorptiometry (DXA) at age 4 years [whole body minus head bone area (BA), bone mineral content (BMC), areal bone mineral density (aBMD), and estimated volumetric BMD (vBMD)]. Volumetric bone mineral density was estimated using BMC adjusted for BA, height, and weight. A higher velocity of 19- to 34-week fetal femur growth was strongly associated with greater childhood skeletal size (BA: r = 0.30, p < .0001) but not with volumetric density (vBMD: r = 0.03, p = .51). Conversely, a higher velocity of 19- to 34-week fetal abdominal growth was associated with greater childhood volumetric density (vBMD: r = 0.15, p = .004) but not with skeletal size (BA: r = 0.06, p = .21). Both fetal measurements were positively associated with BMC and aBMD, indices influenced by both size and density. The velocity of fetal femur length growth from 19 to 34 weeks' gestation predicted childhood skeletal size at age 4 years, whereas the velocity of abdominal growth (a measure of liver volume and adiposity) predicted volumetric density. These results suggest a discordance between influences on skeletal size and volumetric density.
authors.affiliation: MRC Epidemiology Resource Centre, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK.
authors.forename: Nicholas C
authors.initials: NC
authors.lastname: Harvey
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Mahon
authors.forename: Sian M
authors.initials: SM
authors.lastname: Robinson
authors.forename: Corrine E
authors.initials: CE
authors.lastname: Nisbet
authors.forename: M Kassim
authors.initials: MK
authors.lastname: Javaid
authors.forename: Sarah R
authors.initials: SR
authors.lastname: Crozier
authors.forename: Hazel M
authors.initials: HM
authors.lastname: Inskip
authors.forename: Keith M
authors.initials: KM
authors.lastname: Godfrey
authors.forename: Nigel K
authors.initials: NK
authors.lastname: Arden
authors.forename: Elaine M
authors.initials: EM
authors.lastname: Dennison
authors.forename: Cyrus
authors.initials: C
authors.lastname: Cooper
mesh_terms: D000328:Adult; D001823:Body Composition; D015519:Bone Density; D002675:Child, Preschool; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000254:growth & development*; D047109:Fetal Development; D006801:Humans; D008099:Liver / Q000254:growth & development; D008297:Male; D009929:Organ Size; D011247:Pregnancy; D016216:Ultrasonography, Prenatal; D055105:Waist Circumference; D055815:Young Adult