"It is important to note that, contrary to alcohol, benzodiazepines and nicotine, opioids do not have teratogenic potential (3). Thus, special attention needs to be paid to dependence and abuse of legal substances and prescription drugs that can have severe consequences for the foetus and newborn, such as foetal developmental disorders or sudden infant death syndrome (Fetal Alcohol Spectrum Disorders Center for Excellence, 2013; McDonnell-Naughton et al., 2012)."

Source

European Monitoring Centre for Drugs and Drug Addiction, "Pregnancy and opioid use: strategies for treatment," EMCDDA Papers, Publications Office of the European Union: Luxembourg, 2014.