Disclosed is a method for reducing or preventing fetal opioid dependence in a drug dependent or opioid tolerant pregnant subject. The method involves administering to the pregnant subject a composition comprising an opioid antagonist in an amount effective to reduce or prevent fetal opioid dependence, wherein the opioid antagonist a) is orally available or delivered systemically and reaches the circulation of the pregnant subject, b) is substantially excluded from the subjects brain by the blood brain barrier, and c) penetrates the placenta and enters the fetal brain. The method also includes administering the opioid antagonist to the neonate in increasing amounts to facilitate weaning the neonate from continued opioid maintenance.