[Postpartum smoking behavior in women and related factors].

Purpose: To obtain basic data to formulate policies for preventing women from resuming smoking postpartum, this research sought to identify factors affecting continued abstinence and the resumption of smoking among postpartum women who stopped smoking during pregnancy.

Method: An anonymous self-administered questionnaire was sent by mail to 1736 mothers (1030 in City A and 706 in City B, Hyogo Prefecture) whose infants were due for their 18-month health check-up in September and October 2007 and collected on the day of the check-up. Items surveyed were the mother's age, full academic background, number of children, family structure, smoking history, attitude toward smoking and knowledge, husband's smoking history, level of satisfaction with abstinence during pregnancy, and child-rearing concerns. The number and percentage of valid responses were 754 (73.2%) among 1030 mothers in City A and 575 (81.4%) among 706 mothers in City B. This study focused on women who had smoked prior to finding out they were pregnant but stopped smoking during their pregnancy. The responses for each item of the continued abstinent group and the postpartum relapsed group were sorted by city and compared, and factors influencing postpartum smoking behavior were examined using logistic regression analysis.

Results: Of the 754 mothers from City A and 575 mothers from City B, 153 (20.3%) and 105 (18.3%) respectively had smoked before they discovered they were pregnant. Of these, 123 (80.4%) from City A and 88 (83.8%) from City B stopped smoking after discovering they were pregnant on this occasion. Totals of 52 (42.3%) from City A and 45 (51.1%) from City B had resumed smoking at the time of the 18-month health check-up. Logistic regression analysis showed that in cases where the husband smoked the odds ratios for resuming were 42.1 (95% CI: 4.6-387.3) for City A and 13.7 (95% CI: 2.9-65.2) for City B. The odds ratios for those who were pleased they had not smoked during pregnancy were 0.11 (95% CI: 0.04-0.33) for City A and 0.15 (95% CI: 0.04-0.57) for City B. That for mothers from City A who experienced a high level of stress related to child rearing was 6.0 (95% CI: 1.7-21.2).

Conclusion: The findings suggest that having a husband who smokes encourages resumption of smoking postpartum and that those who were pleased they did not smoke during pregnancy continue to abstain postpartum.