Is passive smoking associated with sleep disturbance among pregnant women?
STUDY OBJECTIVE: Pregnant women suffer from sleep disturbance, which may be aggravated by passive smoking. In this study we investigated the effects of passive smoking on sleep disturbance during pregnancy. DESIGN: Two cross-sectional questionnaire surveys conducted in 2002 and 2006. SETTING: Clinical institutions specializing in obstetrics and gynecology that participated in the nationwide surveys: 260 in the 2002 survey and 344 in the 2006 survey. PARTICIPANTS: 16,396 and 19,386 pregnant women in Japan surveyed in 2002 and 2006, respectively. INTERVENTION: N/A. MEASUREMENTS AND RESULTS: Pregnant women exposed to passive smoking were likely to have sleep disturbances, such as subjective insufficient sleep, difficulty in initiating sleep, short sleep duration, and snoring loudly/breathing uncomfortably. Smoking pregnant women had the same sleep disturbances and also experienced excessive daytime sleepiness and early morning awakening. The prevalence of 5 types of sleep disturbance (ins
