State policies pertaining to prenatal substance use have important implications for health outcomes of pregnant women and their infants. However, little is known about the impact of the various types of state-level prenatal substance use policies (i.e., treatment and supportive services; criminal justice initiatives; and health care provider reporting requirements) on substance use disorder treatment admissions. Using data from the 2002-2014 Treatment Episode Data Set - Admissions, we exploited state-level variation in the implementation of different types of policies to assess their impact on pregnant women's admission to substance use disorder treatment. The study found that state-level prenatal substance use policies focused only on the criminal justice sector were negatively associated with the proportion of women of reproductive age who were pregnant upon admission to treatment. Additionally, the implementation of policies that engaged all three sectors was positively associated with the proportion of women of reproductive age who were pregnant upon admission to treatment. These results were consistent across age groups and for both non-Hispanic white women and women of other racial/ethnic groups. The findings imply that states with cross-sector policy engagement around prenatal substance use and policies that take a multifaceted, comprehensive approach are more likely to see an increase in admissions to substance use disorder treatment during pregnancy.