Some individual children escape diagnoses within the FASD continuum in spite of substantial prenatal alcohol exposure (Abel, 1998; May et al., 2013a; Skogerbø et al., 2012; Underbjerg et al., 2012). Maternal risk to the fetus involves the interaction of biological, familial, historical, social, and psychological influences (Gomberg, 1993), and the relative importance of these co-factors to FAS or other diagnoses within the FASD continuum has been demonstrated elsewhere (Abel and Hannigan, 1995; May et al., 2011, in press). This paper focuses on isolating particular measures of alcohol use, for alcohol use is by far the primary risk factor for the physical characteristics and behavioral deficits which define FASD (May et al., 2011, 2013b). In the study population, alcohol is virtually the sole drug used. Alcohol is the teratogen and other variables are predisposing conditions as we currently understand them (Abel and Hannigan, 1995; May and Gossage, 2011).
