Numerous health consequences of children's exposure to maternal smoking have been demonstrated, including increased rates of low birth weight, infant mortality, respiratory infections, asthma, and modest impairments of cognitive development. There is little evidence, however, linking maternal smoking and increased rates of children's behavior problems. Data from the population-based National Longitudinal Survey of Youth were used to investigate the possible association of maternal smoking and behavior problems among 2256 children aged 4 through 11 years. In multiple regression analyses the authors controlled for child's race, age, sex, birth weight, and chronic asthma; family structure, income, and divorce or separation in the prior 2 years; mother's education, intelligence, self-esteem, employment status, chronic disabling health conditions, and use of alcohol during pregnancy; and the quality of the home environment as assessed by the Home Observation for Measurement of the Environment-Short Form to investigate the relationship between maternal smoking and children's behavior problems. The measure of maternal smoking status reflected two levels of smoking intensity (less than a pack per day and a pack or more per day) for each of three different categories of children's exposure: prenatal only (mother smoked only during pregnancy), passive only (mother smoked only after pregnancy), and prenatal plus passive exposure (mother smoked both during and after pregnancy). Measures of children's behavior problems included the overall score on a 32-item parent-reported child Behavior Problem Index (BPI), scores on the BPI's six subscales, and rates of extreme scores on the BPI. Increased rates of children's behavior problems were found to be independently associated with all three categories of exposure to maternal cigarette smoke, with evidence suggesting a dose-response relationship. For example, among children whose mothers smoked both during and after pregnancy, there were 1.17 additional problems independently associated with smoking less than a pack per day (P = .0007) and 2.04 additional problems associated with smoking a pack or more per day (P = .0001). The odds ratio for extreme behavior problem scores for this category of exposure was 1.41 if the mother smoked less than a pack per day (P = .01) and 1.54 if she smoked a pack or more per day (P = .02). These data provide evidence suggesting that increased behavior problems of children should be added to the growing list of adverse child health conditions associated with children's prenatal and passive exposure to maternal smoking.
Feature distribution learning by passive exposure