Objectives: This study examined determinants of and trends in smoking during pregnancy in Finland from 1987 through 1997.
Methods: A repeated cross-sectional investigation of 694,926 women was conducted.
Results: The prevalence of smoking during pregnancy remained similar from 1987 through 1997 (at 15%). In 1997, prevalences of smoking were alarmingly high among young (37%), single (30%), and less educated (25%) women and among women living in northern (20%) and eastern (19%) Finland. These determinants were persistent over time, with the exception of an increase in regional differences.
Conclusions: Despite increasing knowledge of adverse effects, smoking during pregnancy has not declined in Finland over the past decade.