Prevalence of smoking and associated factors among pregnant women in Japan.

This study was conducted to estimate the prevalence of smoking among pregnant women living in Japan and to analyze the factors associated with their smoking behavior.Five hundred institutions with maternity services were randomly sampled from a list of the Japan Association of Obstetricians and Gynecologists. Of these institutions, 260 participated in the survey which was conducted in February 2002. Using a self-reported anonymous questionnaire, a survey on smoking behavior, drinking behavior and sleep status was conducted on pregnant women. Chi-square tests and logistic regression analyses were used to examine the factors associated with their smoking behavior.Data were obtained from a total of 16,414 pregnant women. The prevalence of smoking during pregnancy was 9.9% [95% confidence interval (CI) 9.4%, 10.4%]. The quit rate of smoking among pregnant woman was 61.9% [95% CI 60.4%, 63.4%]. The odds ratios for smoking during pregnancy were significantly higher in women with relatively young age, less schooling, multiparous, exposure to passive smoking, short sleep duration and in women who drank.Smoking among pregnant women remains an important public health problem in Japan. It is necessary to promote antismoking measures based on the results of this study.