Drinking and smoking patterns amongst women attending an antenatal clinic--II. During pregnancy.

This paper describes smoking and drinking patterns during pregnancy amongst a cohort of 2266 women who enrolled at a London antenatal clinic 1982-1983. Only 12% of mothers were non-drinkers before pregnancy, but 44% abstained in the first trimester, 38% in the second and 50% in the third. Before pregnancy 20% of mothers were drinking more than the recommended 10 units of alcohol per week. This dropped to 6% during pregnancy. Mean consumption at each of the three stages of pregnancy was highest amongst those mothers who were the heaviest drinkers before pregnancy. The heaviest pre-pregnancy drinkers were also the least likely to abstain at any point in pregnancy. Of those mothers who were drinking less than 10 units of alcohol per week before pregnancy, 3% increased during pregnancy. Wine was the most popular beverage choice but heavier drinkers were more likely to drink beers and spirits in addition. Before pregnancy 29% of mothers smoked. This dropped to 23% in pregnancy. Consumption levels fell amongst those who continued smoking. The heaviest pre-pregnancy smokers were the most likely to reduce but the least likely to stop. Smoking was positively associated with the level of both pre-pregnancy and pregnancy drinking. The most commonly cited reasons for changes in drinking and smoking habits in pregnancy were concern for the child, concern for self or concern for both. Feeling sick or ill was a more commonly stated reason for reduction of drinking than smoking. Social pressures were important in reducing smoking, but the mass media were quoted as a more important influence in reducing drinking. Mothers who drank more than 10 units of alcohol per week during pregnancy were more likely to be older, of higher social status and primiparous. In contrast those who smoked in pregnancy were more likely to be younger, of lower social status and multiparous. This has important implications for planning antenatal health education.