ALSPAC is one of few studies (currently less than 5) available which has access to extensive phenotypic data measuring birthweight and gestationsal age, related maternal and neonate variables and genomewide genetic data. As an important player in the newly formed Early Growth Genetics (E.G.G.) consortium, ALSPAC is well placed to contribute to a developing line of analyses concerned with the heritability of growth and development related traits. It is for this reason that we seek to enter summary results from available ALSPAC genomewide tests of association with birth weight, gestational age and related traits into the growing meta-analysis for these measurements. As stand alone studies, analysis of these traits in ALSPAC and the National Finnish birth cohort have not revealed sufficiently strong associations to yield statistically robust findings. Consequently efforts to examine the genetics architecture of these traits will require extensive meta-analysis, a process we wish to involve ALSPAC in.