Background: The aim of the study was to describe changes in smoking habits among Danish pregnant women during an eight-year period in relation to changes in sociodemographic and lifestyle factors.
Methods: From 1989 to 1996 all pregnant women attending routine antenatal care at the Department of Gynecology and Obstetrics at Aarhus University Hospital who completed an inclusion questionnaire were invited to participate in the present study (n=27,194). They were asked to complete two additional questionnaires during pregnancy. Apart from smoking habits. these questionnaires provided information on medical and obstetric history together with information on sociodemographic and other lifestyle variables.
Results: The proportion of pregnant smokers decreased from 34% (95% CI: 32%/36%) in 1989 to 21% (95% CI: 19%-22%) in 1996 (p<0.001). The mean number of cigarettes per day remained almost constant during the study period. Stratified and multivariate analyses showed that the results were not confounded by changes in sociodemographic and lifestyle factors.
Conclusions: From 1989 to 1996 a significant reduction in the proportion of pregnant smokers was found. There were no specific campaigns against smoking in pregnancy during this period and the reduction was not associated with changes in sociodemographic and lifestyle factors.