Race, clinical factors and pre-term birth in a low-income urban setting

While infant mortality rates have declined for both White and African-American populations, the perennial two-fold excess in risk for African Americans remains unchanged, and indeed, may have increased since 1985. One potential explanation for the excess risk in African Americans might be racial differences in maternal clinical risk factors, such as prior pregnancy history and pregnancy complications. This paper examines the contributions of such clinical indicators to racial differences in pre-term delivery in a study sample of urban, low-income women, aged 18 to 43 years.

Study participants were enrolled during their first prenatal care visit at one of four hospital-based, prenatal care clinics in Baltimore City. Medical history and pregnancy outcome data were abstracted from clinical records. Multiple logistic regression models were used to assess the independent relationship between race and pre-term birth, after controlling for clinical factors.

Without adjustment for clinical risk factors, African-American women were 1.8 times more likely than White women to have a pre-term birth outcome (95% confidence interval 1.20-2.78). After statistical adjustment for the clinical variables, however, the association between race and pre-term birth was diminished (OR = 1.64, 95% confidence interval: 0.99-2.72). Moreover, the associations between certain clinical risks and pre-term birth were stronger for African-American than White women.

These results suggest that attention to clinical risk factors among African-American women may be an important avenue for reducing Black/White racial disparities in pre-term birth.