Taken collectively, although studies to date are limited, both in number and in scope, it appears important to consider the role of DNA methylation in the pathway from maternal cigarette smoking during pregnancy to later child and adolescent outcomes. It is clear, however, that we have much to learn. Specifically, a better understanding of the mechanisms involved, or what these associations imply, for later offspring outcomes, such as birth weight, cognitive performance, executive function, externalizing behavior, and other health-related phenotypes, including mental health, will be key. In order to accomplish this, we need to elucidate potential etiological pathways linking prenatal exposure-altered DNA methylation and later behavioral deficits or problems in childhood and adolescence. Finally, there is a need to continue to develop novel techniques for assessing the utility of DNA methylation profiles in accessible tissues, such as placenta and umbilical cord blood, further exploring the potential for DNA methylation as a biomarker for prenatal smoke exposure and other adverse prenatal exposures.
