This study demonstrates the importance of examining contextual as well as individual characteristics in order to better determine correlates of ETS avoidance. Behavioral, psychosocial, and social contextual factors may overlap and interfere with health behavior change during pregnancy.56,57
Behavior change efforts focused on only a single risk may be unsuccessful because other risk factors serve as barriers to the desired change.58,59
Using an integrative approach may serve to improve behavioral counseling in healthcare settings.60-62
Evidence presented in this study highlights the importance of addressing interactions between personal, interpersonal, and ETS exposure–specific factors concomitantly. This study replicated previous ETS exposure–specific correlates reported in the literature but also identified several important new factors predicting ETS avoidance during pregnancy that warrant consideration in prenatal care interventions to reduce ETS exposure.
Unique to this study were social contextual factors reflecting the quality of intimate partner relationships. The fact that women without a current partner were more likely to avoid ETS exposure makes intuitive sense; the opportunity for exposure is by definition reduced with one less potential smoker in the social environment. It is also easy to imagine that pregnant women with a child not wanted by the father, or who fear retaliation/IPV, may be very reticent to request that the father not smoke around them. Conversely, partners who want the baby and are not prone to IPV would be expected to be more protective and less likely to smoke around a pregnant woman.
Literature supports this suggestion, but no studies specifically address ETS exposure and these variables. Pregnancy intentions and feelings have been strongly associated with psychosocial and behavioral risks,63-67
including ETS exposure,64
and are influenced by perceptions of the father’s desire to have a baby.64,66,68,69
Maternal health behaviors improve when fathers are involved.70
Men who want to become fathers are more supportive of their partner’s health.71
Similarly, IPV has been associated with increased behavioral risks, including substance use and smoking,72
but not with ETS exposure. Relationship power imbalances,73
and other IPV correlates including learned helplessness or fear of being hurt,74
could influence a woman’s reluctance to prevent ETS exposure, even when such exposures are recognized as harmful. Combined, these findings highlight the need to consider the role that relationship quality, and IPV in particular, may play in affecting a woman’s ability to be assertive about ETS exposure prevention during pregnancy or to establish household smoking bans. Results additionally suggest the need to approach such discussions sensitively and with caution to ensure that women remain safe.
Our results agree with other studies showing that one of the strongest predictors of ETS avoidance is having established a household smoking ban, a factor that has protected adults, children, and infants against ETS exposure.75-78
(The number of cigarettes smoked in the home was equally predictive when tested in a separate multivariate model that excluded the household smoking ban variable.) Bans are reported more often in homes with children79,80
and without smokers.76,77,80
Only one previous study of pregnant women found a similar protective effect.29
Two others demonstrated that in the absence of household bans, expectant fathers continue to smoke,81
and that establishing bans early in pregnancy helps prevent infant ETS exposure postpartum.82
Unfortunately, fewer nonsmokers in this study had household bans than has been reported elsewhere among pregnant/postpartum women,82
low-income minority families irrespective of pregnancy,83
or in households with smokers.79
One possible explanation could be that in this study, younger women (mean age=25 years) were often not the head of household but lived with a parent/grandparent, potentially making it more difficult to establish household bans. Another explanation could be that IPV compromised some women’s ability to make decisions and implement strategies autonomously within their household environment. Additionally, perceived support from others, which has been previously associated with adopting smoking bans to protect infants from ETS exposure82
and with smoking cessation during pregnancy,84,85
but not with ETS exposure during pregnancy, could have played a role. In this study, women who reported that fewer significant others smoked and who perceived greater support in remaining smoke-free were more likely to avoid ETS exposure; however, perceptions of support were lacking in almost half of the population.
Several other findings differed from those in the literature. Demographic characteristics, other than maternal age, were not associated with ETS avoidance, most likely because this was a comparatively homogeneous sample of pregnant, black nonsmokers at high risk. Perceived harmfulness of ETS exposure during pregnancy was low and found to be unrelated to ETS avoidance, whereas in other studies, knowledge of ETS risks was found to be protective.27-29
The lack of an independent association between ETS avoidance and self-confidence in preventing ETS exposure was surprising because it was predictive in one study29
and has been a strong determinant of cessation during pregnancy85-88
and of ETS exposure prevention among infants/children.82,89
Having a partner/household member who smoked had a significant effect on ETS exposure in previous studies,27,28,30
but not in this study. The number of cigarettes partners smoked or the number of household smokers also did not have an effect in this study, potentially because of selection criteria; women in this study were required to have significant others who smoked to be included in the analysis, whereas in other studies all pregnant women were included. Instead, where people smoked was a stronger ETS exposure determinant than whether or how much partners/household members smoked. Further research is needed to better understand discrepancies between this finding and previous study findings.
Study strengths include the focus on identifying correlates of ETS avoidance among pregnant nonsmokers at risk, biomarker verification of self-reports, and identification of several important social contextual factors to consider in preventing ETS exposure during pregnancy. Methods and measures paralleled previous studies examining correlates of smoking cessation during pregnancy and expand on the relatively few studies that focus on ETS exposure.
Of the limitations, the most important relates to the lower detection limits for biomarker validation. Budgetary constraints limited more-sensitive biomarker analysis (e.g., ≤1.0 ng/ml),90
which may have resulted in more ETS avoiders having been reclassified as being exposed to ETS, making the results different. By restricting the upper limit for passive smoke exposure to a salivary cotinine value of 17 ng/ml, some women with high-level exposure may also have been eliminated. Findings were cross-sectional, leaving it unclear whether those classified as avoiders of ETS or being exposed to ETS would remain so classified across the prenatal interval. Study generalizability is limited to lower-income, urban, black women at increased risk who seek prenatal care before 28 weeks gestation. Because these women were enrolled in a larger study based on the presence of selected risk factors, including ETS exposure, these findings are not easily compared to other studies.