American Journal of Epidemiology Advance Access originally published online on February 20, 2007
American Journal of Epidemiology 2007 165(7):734-741; doi:10.1093/aje/kwk107
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
ORIGINAL CONTRIBUTIONS |
Genetic and Environmental Influences on Birth Weight, Birth Length, Head Circumference, and Gestational Age by Use of Population-based Parent-Offspring Data
1 Section for Epidemiology and Medical Statistics, Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway
2 Medical Birth Registry of Norway, University of Bergen and Norwegian Institute of Public Health, Bergen, Norway
3 Division of Epidemiology, The Norwegian Institute of Public Health, Oslo, Norway
Reprint requests to Astrid Lunde, Section of Epidemiology and Medical Statistics, Department of Public Health and Primary Health Care, University of Bergen, Kalfarveien 31, 5018 Bergen, Norway (e-mail: astrid.lunde{at}mfr.uib.no).
Received for publication January 9, 2006. Accepted for publication April 10, 2006.
Familial correlations in birth weight and gestational age have been explained by fetal and maternal genetic factors, mainly in studies on offspring of twins. The aim of the present intergenerational study was to estimate and compare fetal and maternal genetic effects and shared sibling environmental effects on birth weight and gestational age and also on crown-heel length and head circumference. The authors used path analysis and maximum likelihood principles to estimate these effects and, at the same time, to adjust for covariates. Parent-offspring data were obtained from the Medical Birth Registry of Norway from 1967 to 2004. For the analysis of birth weight and crown-heel length, 101,748 families were included; for gestational age, 91,617 families; and for head circumference, 77,044 families. Assuming no cultural transmission and random mating, the authors found that fetal genetic factors explained 31% of the normal variation in birth weight and birth length, 27% of the variation in head circumference, and 11% of the variation in gestational age. Maternal genetic factors explained 22% of the variation in birth weight, 19% of the variation in birth length and head circumference, and 14% of the variation in gestational age. Relative to the proportion of explained variation, fetal genes were most important for birth length and head circumference.
birth weight; family; gestational age; mixed linear model; path analysis; variance components
Abbreviations: MBRN, Medical Birth Registry of Norway; SD, standard deviation
Editor's note: A related article appears on page 742, and an invited commentary on these two articles is published on page 753.
CiteULike 
Connotea 
Del.icio.us What's this?
Related articles in Am. J. Epidemiol.:
- Effect of Consanguinity on Birth Weight for Gestational Age in a Developing Country
- Ghina Mumtaz, Hala Tamim, Mona Kanaan, Marwan Khawaja, Mustafa Khogali, Gerard Wakim, Khalid A. Yunis, and for the National Collaborative Perinatal Neonatal Network
Am. J. Epidemiol. 2007 165: 742-752.[Abstract] [FREE Full Text] - Invited Commentary: Two Studies of Genetic Control of Birth Weight Where Large Data Sets Were Available
- TH Beaty
Am. J. Epidemiol. 2007 165: 753-755.[Abstract] [FREE Full Text]
This article has been cited by other articles:
|
|
 |
|
  S. Cnattingius Commentary: On 'Transmission through the female line of a mechanism constraining human fetal growth'--does it exist? Int. J. Epidemiol., April 1, 2008; 37(2): 250 - 252. [Full Text] [PDF]
|
|
|
|
 |
|
 H. K. Gjessing and R. T. Lie Biometrical modelling in genetics: are complex traits too complex? Statistical Methods in Medical Research, February 1, 2008; 17(1): 75 - 96. [Abstract] [PDF]
|
|