The percentage of pregnant participants screened for the MOTHER study who reported current cigarette smoking is more than four times higher than in the general pregnant population (1
). The high rate of cigarette smoking is alarming because continued smoking during pregnancy is associated with diverse adverse health effects (4
). The fact that this high rate of cigarette smoking did not differ compared to the other drug-dependent or methadone-maintained samples regardless of pregnancy status further illustrates the critical imperative to address cigarette smoking cessation in pregnant and non-pregnant substance-dependent populations (10
), especially for those individuals who are opioid-dependent. Interestingly, comparing the MOTHER screening sample to any of the samples showed similarities in the average age [14 or 15 years] at which smoking was initiated and duration of continued smoking. These ages meet the definition of “young initiators.” Those individuals who initiate smoking by age 15 compared to those who start smoking after this age, were less likely to cease cigarette smoking and reported higher levels of nicotine dependence than the older initiators (21
). The high rates of cigarette smoking at a young age in all samples emphasize the urgent need to focus smoking prevention messages toward youths. Specialized information and intervention for youth at risk for or already engaging in other substance use behavior may also be needed (22
The MOTHER screening sample demonstrated both risk and protective factors for smoking during pregnancy. More women in the MOTHER screening sample were White and married compared to pregnant drug-dependent samples (15
). Being White can predict smoking during pregnancy (24
). Being unmarried has been among five independent factors related to cigarette smoking (25
There are several limitations of this study. First, data were collected as part of a larger on-going randomized double-blind study and previously-published data were used for comparative purposes. As a result, equivalent measures were not available across all the comparison samples. Like previous studies, this study relies on commonly used broadly-defined measures of smoking. A prospective trial examining smoking history and current smoking could include more comprehensive and sensitive measures and yield results supporting stronger conclusions. However, the present data are an important first step in the development of direct comparisons between smoking treatments for this patient population. Second, the sample sizes of the examined groups are variable and may limit the power to detect differences in some instances. However, this limitation is tempered by the fact that differences in the expected direction were observed on most measures of interest. A larger sample size would have allowed for participants to be further categorized according to smoking severity and perhaps yielded additional interesting outcomes.
Despite these limitations, the present study provides some of the first data examining the prevalence of smoking in pregnant women seeking opioid–agonist treatment. While the health risks of smoking during pregnancy are well known, future research must focus on several important issues. First, characterizing how these risks are exacerbated or mitigated in pregnant drug-dependent women. Second, how the addictive disorder that is the focus of treatment and smoking together fuel negative bio-behavioral outcomes in these women and their offspring. Third, developing and implementing effective behavioral and medication treatments to reduce and eliminate smoking over the course of pregnancy to improve maternal and child health is imperative.