A Typology of Substance Use Among Pregnant Teens in the United States

Background and Purpose.  Prior research on adolescent substance use and sexual risk behavior suggests that substance use and teen pregnancy are profoundly interrelated. Specifically, evidence suggests that teens—in general—tend to report elevated levels of substance use prior to conception and substantial reductions in use during pregnancy.  However, it is likely that a degree of heterogeneity can be observed with respect to the patterns of adolescent substance use prior to and during pregnancy.  For instance, some youth may occasionally use alcohol and cannabis prior to pregnancy, but discontinue use altogether during fetal gestation. Others may use these substances prior to pregnancy and then continue to use alcohol, cannabis, or other substances throughout pregnancy.  The aim of the present study is to identify subgroups of pregnant adolescents (ages 12-17) on the basis of variables measuring the past 12-month and past 30-day use of an extensive array of licit and illicit substances.

Method. The present study employs data from a large, population-based study (National Survey on Drug Use and Health) of adolescents in the United States between 2002 and 2012.  We employ latent class analysis to identify latent subgroups of pregnant adolescents (ages 12-17; n = 810) on the basis of variables measuring the past 12-month and past 30-day use of alcohol, cannabis, cocaine, hallucinogens, methamphetamine, stimulants, tranquilizers, and ecstasy. We utilized past 12-month and past 30-day measures as relative approximations for substance use prior to and during pregnancy, respectively. 

Results. Results revealed a four class solution. Classes were identified as Class 1: Abstainers (n = 344, 42.47%), Class 2: Drinkers (n = 303, 37.41%), Class 3: Alcohol and Cannabis Users (n = 77, 9.51%), and Class 4: Polydrug Users (n = 86, 10.62%).  The Polydrug Users class had the highest proportion of youth who were in late adolescence (75.58%), non-Hispanic white (54.65%), high-income (13.95%), and in their first trimester of pregnancy (58.33%). Polydrug Users represented roughly one-tenth of all pregnant adolescents, but accounted for more than three-fifths (60.34%) of all “other illicit drug” use disorder diagnoses.

Conclusions and Implications. Although the use of a past 30-day measure of substance use does not provide an inscrutable approximation of use during pregnancy, the identification of the Alcohol and Cannabis Users and Polydrug Users classes points to subgroups of pregnant teens that may be of particular relevance to neonatal health and prevention efforts.  Perhaps of greatest concern is the clear pattern of continuity from past-12 month to current (i.e., past 30-day) use despite the fact that a sizable minority of class members are in the later stages of pregnancy.  These data seem to suggest that past 12-month use of both alcohol and marijuana may be viewed as a “flag” for continued use of these and other illicit substances during the early and, indeed, mid-to-later stages of pregnancy. Findings suggest that future research should carefully examine the links between the co-occurring use of alcohol and cannabis prior to pregnancy and the continued use of these and other substances during fetal gestation.