Changes in smoking behavior between first and second pregnancies

To assess changes in maternal smoking behavior at the second pregnancy.

First and second birth certificates were matched for 5241 white and black mothers in Kansas City, Mo, who had singleton births between 1994 and 2003.

The pregnancy-smoking quit rate was 24.9%, and the pregnancy-smoking initiation rate was 4.8%.

Twenty-five percent of women who smoked and 5% of women who did not smoke during their first pregnancy changed their behavior during their second pregnancy. These findings reflect a minimal net shift in pregnancy-smoking between pregnancies and support the importance of persistent antismoking socialization that is independent of a pregnant woman's previous pregnancy-smoking status.