Birth weight for gestational age as a health indicator: Birth weight and mortality measures at the local area level

Abstract

Foetal growth is of interest not only as a predictor of pregnancy outcome and of infant and child health, but also of subsequent adult disease. Birth weight (BW) standardized for gestational age and sex (BWSDS) is a measure of foetal growth. The aim of this paper was to study the BWSDS as a health indicator in comparison with other pregnancy outcome measures such as crude BW, the low birth weight (LBW) rate and the pre-term birth rate by correlation to mortality rates and to a socioeconomic area index, at local area level in the city of Göteborg, Sweden 1973-1986. The results showed that BWSDS had a statistically significant correlation to mortality rates in the adult population (-0.58 to -0.70) and to a socioeconomic area index (0.89) and a general pattern of closer relationship to these measures compared to the other pregnancy outcome measures at the local area level. This indicates that BWSDS, in comparison with the BW, LBW rate and the pre-term birth rate, has at least as good (or better) properties as a health indicator. The BWSDS, representing the main perinatal population, has a broader representativity than merely being an indicator of foetal health in a restricted sense. Birth weight for gestational age is found to be suitable as a health indicator at the local area level.