Objective: To determine whether pregnancy-smoking rates have changed in last decade.
Methods: Retrospective cohort study of 67,395 pregnancies in Kansas City over 2 epochs, 1993-1997 and 1998-2002, using computer files of birth certificates.
Results: Overall pregnancy-smoking rates decreased from 18.1% (95% CI=17.7-18.5%) to 14.2% (13.8-14.5%). Among smokers, there was a distribution shift toward light smoking; light [39% (38.9-40.3%) vs 49% (47.6-50.4%)], moderate [36.8% (34.8%-38.8%) vs 34.4% (32.1-36.7%)], and heavy [23.1% (21.9-26.3%) vs 16.6% (14-19.1%)].
Conclusions: The results suggest decreasing heavier smoking. However, the trend toward light smoking suggests decreasing self-reporting. These findings highlight the dilemma in using self-reports for public health policy and emphasize the importance of antismoking socialization for all pregnancies.