Adequacy of Prenatal Care and Pregnancy Outcomes in Cigarette Smoking and Nonsmoking Mothers

Abstract

This study investigated whether the higher risks of adverse pregnancy outcomes for mothers who smoked cigarettes during pregnancy differed based on whether or not they received adequate prenatal care. Data were extracted from matched birth and infant death records, obtained from the North Carolina State Center for Health and Environmental Statistics for the years 1988–1990 for Guilford County, North Carolina. The indicator of adequacy of prenatal care was a Standard Protocol of Prenatal Care recommended by the American College of Obstetricians and Gynecologists. Preterm births, low birth weights, and infant deaths were the main outcome measures. Among smokers, adequate prenatal care was associated with significantly (p < 0.05) lower rates of preterm births [rate ratio (RR) = 0.68], low birth weight among full-term births (RR = 0.49), and infant death (RR = 0.50). Among nonsmoking mothers, adequate prenatal care was also associated with significantly lower rates of preterm births (RR = 0.55) and of infant deaths (RR = 0.29), but not of preterm or full-term low-birth-weight infants. Analyses indicated that race and maternal age were not factors that influenced the effects of adequate care for smoking or nonsmoking mothers. These findings suggest that adequate prenatal care appears to have substantial benefits for smoking as well as nonsmoking mothers and that the major benefit to smoking mothers may be in the reduction of full-term low-birth-weight infants.