Smoking cessation during pregnancy

Abstract

Smoking habits, attitudes to smoking, and sources of information were monitored at three antenatal clinics (ANC) in suburban Stockholm, Sweden, during 1987-88. A questionnaire was mailed to pregnant women and their partners in a pre-intervention study.

Of 582 women enlisted at the ANCs, 433 (74%) were included. 253 (58%) women and 230 (53%) partners responded. Thirty percent of the women were smokers at the start of pregnancy, compared with 25% of the men. During pregnancy 18% continued to smoke, and after the birth 21% were smokers. The male partners stopped or decreased less often. The number of heavy smokers decreased considerably during and after pregnancy. The women were more prone to stop smoking if the partner was a non-smoker. 87% made some restriction in their smoking habits after their baby was born.

The overall attitude was against smoking and for information about tobacco hazards during pregnancy. A minority stated that they were "much influenced" by information from the ANC, the partner, or media such as TV. Of the three, the view of the partner seemed to be the most important factor of influence. During the year following the first study, the women at one health centre, and their partners, were given special attention to try to change their attitudes to smoking, while one of the other two centres acted as control and provided the usual care. In a post-intervention study, 385 women were included. 216 (56%) participated, compared with 194 men.

Smoking decreased during and after pregnancy at both the intervention and the control health centres. Attitudes to smoking changed little. The impact from the partner remained the most important source of influence on attitudes to smoking, while the influence from the ANC remai ned the least important. Typical for a woman who stopped smoking, was that she was more influenced by the ANC, her partner, and TV, and her partner smoked less. During a 10-month period in 1994-1995, women who smoked at the onset of pregnancy and attended any of nine ante-natal clinics (ANC) were asked to participate in a semi-structured interview concerning smoking and pregnancy. She was asked about smoking habits. attitudes, LOC( describing to what extent a person is in control of life events), general health, sleep and social situation. Her carbon monoxide in expiratory air was also determined. One month after delivery one hundred of them, having had successful deliveries, were asked again to report present smoking habits, the occurrence of nausea and how much sick-leave she had had during her pregnancy. In comparison to earlier studies, fewer women were registered as smokers and more women stopped smoking. Several circumstances, like smoking habits of the partner, occurrence of passive smoking at home, various attitudes linked to the smoking issue, LOC, general health or attitudes to anti-smoking pamphlets showed no correlation to discontinuation of smoking. In contrast, younger age, starting smoking at an older age, earlier childlessness, light smoking, high level of education, positive support from the partner and having lived with non-smoking parents were associated with stopping smoking. In contrast to earlier findings younger women were more likely to stop smoking and those who lived with a smoking partner were not less likely to stop smoking. CO levels in expired air correlated well with the reported smoking status. Blood samples from 509 pregnant women from one ANC in the Blekinge County from 1993-95 were analysed. In 496 cases smoking habits were recorded together with other background factors.

In stated non-smokers, 13 had cotinine levels between 6 and 17.5ng/ml, suggesting substantial exposition to environmental smoke. 25 women who reported to be non-smokers had cotinine levels consistent with active smoking. Another 19 women reported to be light smokers but had values above the median of those being heavy smokers. The results indicate that non-disclosure of smoking or underestimation of the number of cigarettes, during pregnancy is not uncommon.