摘要:Objectives . We sought to estimate the effect of universal implementation of a clinic-based, psychosocial smoking cessation intervention for pregnant women. Methods . We used data from US birth certificates (2005) and the Pregnancy Risk Assessment Monitoring System (2004) to estimate the number of women smoking at conception. To calculate the number of women eligible to receive the cessation intervention, we used estimates from the literature of the percentage of women who quit spontaneously (23%), entered prenatal care before the third trimester (96.5%), and disclosed smoking to their provider (75%). We used the pooled relative risk (RR) for continued smoking from the 2004 Cochrane Review as our measure of the intervention's effectiveness (RR = 0.94). Results . We estimated that 944 240 women smoked at conception. Of these, 23.0% quit spontaneously, 6.3% quit with usual care, and an additional 3.3% quit because of the intervention, leaving 67.4% smoking throughout pregnancy. The calculated smoking prevalence in late pregnancy decreased from 16.4% to 15.6% because of the intervention. Conclusions . Universal implementation of a best-practice, clinic-based intervention would increase the total number of quitters but would not substantially reduce smoking prevalence among pregnant women. An extensive body of literature demonstrates that maternal smoking during pregnancy has numerous adverse effects on maternal, fetal, and infant health, including increased risk of abruption, placenta previa, premature rupture of membranes, preterm birth, fetal growth restriction, and sudden infant death syndrome. 1 , 2 Increased awareness of the dangers of smoking and the implementation of tobacco control policies likely have contributed to declines in smoking during pregnancy over recent decades, but the prevalence remains unacceptably high. A goal of Healthy People 2010 is to decrease the percentage of women who smoke during pregnancy to 1.2%, 3 but recent estimates indicate that more than 16% of pregnant women still smoke. 4 Numerous approaches to prenatal smoking cessation have been studied, including counseling, cognitive and behavioral therapy, hypnosis, acupuncture, and pharmacotherapy. Because of concerns about the safety and efficacy of pharmacologic therapies, approaches such as nicotine replacement therapy or use of bupropion are recommended for consideration only in women who fail nonpharmacologic methods and in whom the potential benefits of the therapy outweigh the unknown risks of the medications. 5 , 6 Many efforts to further decrease smoking among pregnant women focus on clinic-based cessation interventions. Current recommendations for a first-line approach (beyond simply advising pregnant smokers to quit) advocate extended or augmented psychosocial intervention delivered in a clinical setting. 5 , 6 This endorsement is based on numerous studies that found that augmented cessation interventions were more effective than was usual care in achieving smoking cessation during pregnancy. An augmented psychosocial intervention is commonly implemented in the form of the 5 A's (ask, advise, assess, assist, and arrange); clients receive a provider-administered, 5- to 15-minute counseling intervention and self-help materials. This approach, which can be integrated into routine clinical care, is endorsed by the American College of Obstetricians and Gynecologists as best practice for smoking cessation during pregnancy. 6 A study that used findings from a previous study that an intervention would achieve a 30% to 70% improvement over baseline quit rates 7 found the 5 A's to be cost effective or cost neutral. 8 To date, however, the efficacy of an augmented clinic-based intervention in reducing the prevalence of smoking during pregnancy at the population level has not been formally evaluated. Therefore, we sought to estimate the number of additional women who would stop smoking during pregnancy and the change in US prenatal smoking prevalence if an augmented psychosocial intervention were implemented universally.