Is there an increased lability in parents' smoking behaviour after a childbirth?

To test our hypothesis that there is an increased lability in parents' smoking behaviour after a childbirth, and to search for demographic factors associated with lability in parents' smoking behaviour.

A one month, prospective questionnaire study.

Maternal and child health centres in Oslo, Norway.

222 families in which at least one adult was smoking were enrolled in the study. 37 families dropped out (16.7%) and 185 families completed both questionnaires.

Changes in daily smoking, smoking quantity, and practical measures to prevent passive smoking by the children, as assessed by parental reports.

Families with a child aged less than one year (infant) were more likely to make one or another positive change (quit, reduce, stop smoking indoors, stop smoking in living rooms) than families with only older children. There was a trend for families with an infant to make negative changes more often (start smoking, increase) as well. Older parents made positive changes more often than younger ones. Single parents were less likely to make positive changes.

The study indicates that there is an increased lability in parents' smoking behaviour after a childbirth.