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Estimated probability of preterm delivery by maternal age, stratified by level of neighborhood deprivation (low, medium, and high), for (a) multiparous White nonsmokers, (b) multiparous White smokers, (c) multiparous Black nonsmokers, and (d) multiparous Black smokers: 8 US geographic areas, 1995–2001.
Note. The sample size was n = 182 938.
