Although the percentage of pregnant patients who use illicit drugs is relatively low, the effects can be devastating on both mother and fetus-loss of custody, growth restriction, placental abruption, and death. The practicing obstetrician may be unfamiliar with the various presentations of chemical dependency in pregnancy, including intoxication and withdrawal, and difficulty in making the diagnosis. The obstetrician is in the unique situation of being responsible for the safety of both mother and fetus, which may involve engaging the unwilling patient in treatment.