Smoking during pregnancy rates trends in a high smoking prevalence state, 1990-2009.

OBJECTIVE: To assess the trends for smoking during pregnancy for whites and blacks in Missouri, a state with a high prevalence of smoking, for the period 1990-2009. METHODS: Retrospective cohort study of annual pregnancy smoking rates recorded on birth certificates. Trends were assessed by regression analyses for all births, births to whites and blacks, births to whites and blacks in aggregate, and by zip codes within the combined jurisdictions of Kansas City, St Louis City, and St Louis County. Zip code smoking during pregnancy rates matched with the respective zip code race-specific population compositions were analyzed by chi-square tests. RESULTS: Smoking during pregnancy rates trends for whites and blacks differed significantly during the 2 decades. Although rates for whites declined over time, they were relatively stable from 1999 through 2007. Rates for blacks exhibited a steep decline in the early 1990s, remaining stable after 1995. Within the combined jurisdictions, rates for blacks who smoked during pregnancy surpassed those of whites beginning in 2001. The lack of prenatal care for either race was the only maternal characteristic consistently associated with lack of reduction in smoking during pregnancy. There also were no declines among young birth mothers of either race who had 12 or fewer years of education. Rates of smoking during pregnancy for blacks and whites were highest in zip codes with a ≥50% black population. CONCLUSIONS: Rates for smoking during pregnancy for whites and blacks in Missouri overall have not changed appreciably from 2000 to 2009. Beneficial antismoking during pregnancy effects that could reverse this trend may be achievable via improved access to prenatal care, especially for young, uneducated women.