tional level, and women who initiated smoking during their adolescent years (DiClemente et al. 2000; Goldenberg et al. 2000; Pickett et al. 2003; Yu et al. 2002). Tobacco use among pregnant women also occurs at greater rates among women who engage in other harmful health behaviors, are most heavily addicted to tobacco, and have the fewest psychosocial resources to overcome the addictive behavior (e.g., DiClemente et al. 2000; Goldenberg et al. 2000). It is perhaps important to recognize that these women represent a population subgroup that may be most resistant to cessation efforts given that they appear to have opted to smoke despite prevailing anti-smoking social norms and messages concerning the harm of smoking in general and during pregnancy (DiClemente et al. 2000).
Maternal smoking remains the single most important modifiable cause of poor pregnancy outcome in the United States, accounting for a significant proportion of babies with low birth weight, pre-term births, and perinatal deaths such as sudden infant death syndrome (SIDS) (Orleans et al. 2000). Such negative effects have been shown to occur even at moderate levels of smoking (e.g., less than eight cigarettes per day). Further, studies have shown that maternal smoking during pregnancy contributes to a range of health and developmental complications for children, including changes in fetal brain and nervous system development, respiratory illnesses, ear infections, language delays, higher activity, increased tantrums, and lower social competence (e.g., Anderson and Cook 1997; Ashmead 2003; Di Franza and Lew 1995; Faden et al. 2000; Slotkin 1998; Wisborg et al. 1999). These risks related to maternal smoking prompted the Healthy People 2010 objective to reduce smoking rates among pregnant women to no more than 2 percent (DHHS 2000).
Many women quit smoking at some point during their pregnancy, with most cessation attempts occurring upon first learning about their pregnancy status (e.g., Pickett et al. 2003). Cessation efforts may be permanent, limited to the duration of their pregnancy, or sporadic during pregnancy, while other women simply reduce their amount of smoking. Data from the PRAMS study showed that an average of 42.5 percent of the women quit smoking at some point during their pregnancy, with quit rates increasing from 1993 through 1999 (Colman and Joyce 2003). Data from the NHIS 1991 Pregnancy and Smoking Supplement showed that while almost 40 percent of the pregnant women quit smoking for at least 1 week, almost half of these women resumed smoking at some point during their pregnancy (Pickett et al. 2003; see also Yu et al. 2002). Quit attempts were most prevalent in the first trimester, although attempts at smoking cessation occurred throughout the pregnancy.
Quit rates among pregnant women vary by demographic factors, with cessation more likely among adolescents, older women, women at first pregnancy, more educated women, Hispanic women, women with lower nicotine dependence, and women who smoke fewer than 10 cigarettes per day (Colman and Joyce 2003; Pickett et al. 2003; Yu et al. 2002). Low SES also appears to be a primary characteristic that distinguishes women who quit from women who continue smoking during pregnancy (e.g., Panjari et al. 1997; Quinn et al. 1991). Importantly, these women are subject to the cumulative stress of the range of physical and psychosocial conditions that are associated with lower SES. They are known to have more emotional problems, less social support, fewer financial resources, and residential instability (Paarlberg et al. 1999; Panjari et al. 1997). Too often, the pregnancy may have been unplanned, possibly resulting in the woman viewing her pregnancy as an additional stressor. Tobacco use may represent, in effect, a way of coping with stress.