Geographical variation in relationships between parental body size and offspring phenotype at birth.
BACKGROUND
Size and body proportions at birth are partly determined by maternal body composition, but most studies of mother-baby relationships have only considered the effects of maternal height and weight on offspring birth weight, and few have examined the size of effects. Paternal size and body composition also play a role, primarily through the fetal genome, although few studies have investigated relationships with neonatal phenotype.


METHODS
Data from the UK, Finland, India, Sri Lanka, China, DR Congo, Nigeria and Jamaica were used to investigate the effects of maternal measures (derived at 30 weeks' gestation, n=16,418), and also paternal size (n=3,733) on neonatal phenotype, for singleton, live-born, term births.


RESULTS
After accounting for variation in maternal size and shape across populations, differences in neonatal phenotype were markedly reduced. Mother-baby relationships were similar across populations, although some were stronger in developing countries. Maternal height was generally the strongest predictor of neonatal length, maternal head circumference of neonatal head and maternal skinfold thickness of neonatal skinfolds. Relationships with maternal arm muscle area were generally weak. Effects of paternal height and body mass index were weaker than the equivalent maternal measurements in most studies.


CONCLUSIONS
Differences in maternal body composition account for a large part of the geographical variation in neonatal phenotype. The size of the effects of all maternal measures on neonatal phenotype suggests that nutrition at every stage of the mother's life cycle may influence fetal growth. Further research is needed into father-baby relationships and the genetic mechanisms that influence fetal growth.
Leary
Sam
S
Medical Research Council, Environmental Epidemiology Unit, University of Southampton, Southampton, UK. s.d.leary@bristol.ac.uk
Fall
Caroline
C
Osmond
Clive
C
Lovel
Hermione
H
Campbell
Doris
D
Eriksson
Johan
J
Forrester
Terrence
T
Godfrey
Keith
K
Hill
Jacqui
J
Jie
Mi
M
Law
Catherine
C
Newby
Rachel
R
Robinson
Sian
S
Yajnik
Chittaranjan
C
D000328:Adult; D000886:Anthropometry; D001724:Birth Weight / Q000235:genetics* / Q000502:physiology*; D001823:Body Composition / Q000235:genetics / Q000502:physiology; D001827:Body Height / Q000502:physiology; D015992:Body Mass Index; D049628:Body Size / Q000208:ethnology / Q000235:genetics* / Q000502:physiology*; D002681:China / Q000208:ethnology; D003223:Congo / Q000208:ethnology; D005006:Ethnicity; D005220:Fathers; D005260:Female; D005387:Finland / Q000208:ethnology; D005843:Geography; D006801:Humans; D007194:India / Q000208:ethnology; D007231:Infant, Newborn / Q000502:physiology*; D007563:Jamaica / Q000208:ethnology; D008297:Male; D009035:Mothers; D009549:Nigeria / Q000208:ethnology; D010641:Phenotype; D011247:Pregnancy; D013188:Sri Lanka / Q000208:ethnology; D006113:United Kingdom