Smoking pattern during pregnancy in Hong Kong Chinese

Background: While the prevalence of young female smokers is rising among the Hong Kong Chinese population, data on their smoking pattern during pregnancy are limited.
Aims: To investigate the smoking habit of Hong Kong Chinese women and their partners during pregnancy.
Methods: Postal questionnaires were sent to 479 couples to explore their smoking patterns during pregnancy at one to two years after the index delivery.
Results: Questionnaires were completed by 247 subjects. Among 117 women who were ever-smokers, 26% had stopped smoking before the index pregnancy, while 60% stopped and 14% reduced smoking during the pregnancy. Most women stopped smoking in the first trimester (93%) and prior to the first antenatal visit (79%). Those who used to smoke fewer cigarettes before pregnancy were more likely to stop smoking during pregnancy but women with a history of recreational drug use were more likely to continue smoking during pregnancy. The post-partum smoking relapse rate was 59% in women who had stopped smoking before or during their pregnancy. Only 2.6% of the partners who were ever-smokers stopped smoking before the pregnancy while smoking habits remained unchanged in 52%.
Conclusions: Approximately one-fifth of an unselected sample of Hong Kong mothers had a history of smoking prior to pregnancy. Pregnancy is an opportune time to implement smoking intervention programs for female smokers and their partners with an emphasis on the maintenance of post-partum smoking abstinence.