Decline in the United States black preterm/low birth weight rate in the 1990s: can the economic boom explain it?

PURPOSE: Macroeconomic improvements have been posited as an explanation of the decline in the Black preterm birth rate during the 1990s. This study assessed whether decreasing unemployment explained the decline in preterm, low birth weight births (PT-LBW) for Black women. METHODS: United States singleton births to non-Hispanic Black women ages 18 and over, conceived between 1990 and 2001, were pooled to examine PT-LBW trends by level of social advantage (approximated by education and marital status). The impact of the state-level unemployment rate in the first and second trimester of pregnancy was evaluated in multiple logistic regression models. RESULTS: During the 1990s, PT-LBW declined 11% among disadvantaged (unmarried, less than high school educated) Black women. Although the unemployment rate and PT-LBW were positively related, decreases in unemployment did not explain the decline in PT-LBW. Instead, improvements in prenatal care utilization and smoking behavior largely accounted for the temporal trend. CONCLUSIONS: Macroeconomic improvements, measured by unemployment, only marginally contributed to the Black PT-LBW trend in the 1990s. To effect further reductions, future studies should investigate other possible determinants of the proximate behavioral changes that did explain the trend (e.g., Earned Income Tax Credit expansions, increased, cigarette taxes/smoking legislation).