Prescription opioid use among women of reproductive age and pregnant women is relatively common. In this article, we examine whether state opioid control policies affected prescription opioid use and, in turn, infant health and maternal behaviors. We conduct several types of analyses including reduced form analyses of the effect of state policies on infant health and maternal behaviors, and instrumental variables analyses of the effects of prescription opioid use on infant health and maternal behaviors. Results from our analysis suggest that reductions in prescription opioid use because of state prescription opioid control policies have improved infant health modestly at the population level with larger implied effects at the individual level. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.