Single motherhood and low birthweight in Spain: Narrowing social inequalities in health?

Nonmarital childbearing is becoming an increasingly common path to family formation in Spain. The proportion of births to unmarried mothers has increased from 2% in 1975 to 30.2% in 2007. Along with this marked increase, there has been an important shift in the sociodemographic profile of unmarried mothers. This study focuses on the impact of mothers' marital status on the health status of their newborns, using low birthweight as an indicator. We are interested in examining how the impact of mothers' unmarried status on birth outcomes changes as nonmarital childbearing shifts from a marginal to a relatively common behaviour. The results of the analysis reveal that the health disadvantage gap between marital and nonmarital births has narrowed significantly over the past decade in Spain. We argue that diminishing selection processes and increasing social acceptance could explain the declining significance of marital status as a risk factor for low birthweight.