Few studies have considered the differing impact of socioeconomic factors on pregnancy outcomes among racial subgroups. We assessed pregnancy outcome by race, education, and income (poverty index), using data from the Pregnancy, Infection, and Nutrition Study, a cohort study of preterm birth in central North Carolina, using binomial regression. Poverty was associated with an increased risk of preterm birth only among African Americans with 12 or more years of education (RR=1.6, 95% CI: 1.1, 2.2). White participants with both a low level of education and an income below the poverty line were at increased risk of preterm birth (RR=1.7, 95% CI: 1.1, 2.7). White women with 12 or more years of education had increased risk of small-for-gestational-age birth (SGA, defined as <10th percentile of birth weight for gestational age) associated with poverty status (RR=1.7, 95% CI: 1.1, 2.7). Socioeconomic indicators appear to have complex joint effect patterns among racial subgroups, perhaps because the material and psychological implications of education and income status differ between groups.