International variations in intrauterine growth

International variations in intrauterine growth have consistently been judg ed in terms of average birthweight, low birthweight or birthweight-for-gest ational age criteria. Neither of these provide an appropriate assessment of fetal growth. Notwithstanding these limitations the available evidence indicates that var iations in growth, both within and among populations, relate predominantly to differences in the prevalence of factors that restrain growth rather tha n to inherent differences in growth potential. The evidence also indicates that differences in the frequency of low weight-fbr-gestation among populat ions do not only reflect factors that restrict fetal growth. They are also intimately linked to variations in gestational age and to frequencies of pr eterm birth in particular. Hence, if weight-for-gestational standards are to become more informative a nd more universally applied than they have been so far, it may be useful to acknowledge their limitations more explicitly and simplify their implement ation in a wider range of communities. (C) 2000 Published by Elsevier Scien ce Ireland Ltd.