Which women stop smoking? A population-based study of 403 pregnant smokers

To describe, in detail, the smoking cessation process during pregnancy, and to find out which women are most and least successful at reducing or giving up smoking.

Prospective, population-based study.

All antenatal clinics in Kronoberg County in southern Sweden.

Four hundred and three women, smoking at the time of conception, and registered for antenatal care in the period June 1993 to September 1994.

Self-reported number of cigarettes smoked per day and percentage of smoking women in different weeks of pregnancy. Noted by midwives on special forms.

At the time of registration at the antenatal clinic, the proportion of smoking women had fallen from 100% to 76%, and at the postpartum check-up, the proportion had fallen further to 56%. For the women still smoking, the mean number of smoked cigarettes per day fell from 14.1 before the pregnancy, to 8.6 in week 12, and 6.3 in week 40, and then rose to 9.5 after the pregnancy. Heavy smokers and women with smoking partners continued smoking to a greater extent, as did multiparae and women in unqualified jobs.

The individual anti-smoking advice given during pregnancy should be aimed primarily at these risk groups, and the partner should be involved in the woman's attempt to cease smoking. There is much left to be done at the antenatal clinic, as more than half of the women were still smoking a few months after pregnancy.