Poverty and race are associated with preterm birth according to a cross-sectional study of the US population. Among mother-child dyads in households with incomes below the federal poverty level, preterm birth rates increased significantly. A study published on MedPage Today analyzed these associations in low-income families. The main finding is the growing trend of premature births in poor households. Race is another factor affecting the risk of preterm birth. The study focused on mother-child dyads in the US.