Despite the opposition of medical and public health professionals, several state legislatures are considering laws that permit child abuse charges for substance use during pregnancy. We reviewed legal decisions regarding women charged with a crime against a fetus or child as a result of substance use during pregnancy. We identified 24 judicial opinions published between 1977 and 2015 in cases involving 29 women prosecuted in 19 states. Charges included child endangerment, child abuse, drug delivery, attempted aggravated child abuse, chemical endangerment of a child, child neglect, child mistreatment, homicide, manslaughter, and reckless injury to a child. The substances related to the charges included cocaine, heroin, methamphetamine, marijuana, and prescription pills. Proceedings resulted in dismissal of the charges or convictions overturned for 86.2 percent of the women. In all of the cases, the judicial decision depended on the disposition of the question of whether, for the purpose of adjudicating the criminal charges, a fetus is a child. The balance in the courts in favor of treating substance use during pregnancy as a medical problem depends on the definition of a child for the purposes of criminal statutes. Professional advocacy may best be directed at state legislatures., (© 2017 American Academy of Psychiatry and the Law.)