Choices4Health: Intervention to Prevent Substance-exposed Pregnancy

A randomized group design (N = 240) will be used to test the efficacy of the C4H-C and C4H-T interventions relative to Brief Advice (BA) to reduce the risk of substance-exposed pregnancy) SEP in preconception women of childbearing age. Follow-up assessments will be conducted at 3, 6, and 9 months. Each of the substances targeted in this study (risk drinking, cigarette smoking, and marijuana use) is commonly used relative to other substances and is singly or jointly associated with risk for poor fetal outcomes. Thus, women who are not using effective contraception (i.e., use of effective birth-control methods during all vaginal intercourse) and have any one or more substance-risk behaviors in the 30 days before intake will be eligible for the study. Urn randomization will be used to stratify women on all three substance-risk behaviors to ensure a balanced number of women presenting with alcohol-exposed pregnancy (AEP), tobacco-exposed pregnancy (TEP), and marijuana-exposed pregnancy (MEP) risks across the three study conditions. To address risk distribution for women who present with more than one risk behavior the urn randomization will also be programmed to balance single risk and multiple risk women across the study conditions. In sum, the urn randomization will include four assignment criteria: AEP, TEP, MEP, and multiple risks. Finally, different numbers of women will be needed for each type of substance-exposed pregnancy risk in order to provide sufficient power for the investigator's analytic tests. For example, approximately 25% more women at risk of AEP are required than for TEP to attain the same power. The investigators will include over sampling rules and stopping rules to ensure adequate recruitment for AEP, TEP, and MEP.