Addiction is a psychological and physical condition that arises from the interaction between the psychoactive substance and the human body, and any addictive pregnancy is considered risky and can leave many negative consequences. The most common complications that arise as a result of consuming opiates and psychoactive substances during pregnancy are spontaneous abortion, intrauterine death, intrauterine growth failure, premature delivery, placental abruption and placental insufficiency, low birth weight, sudden baby infant syndrome, newborn abstinence syndrome and later difficulties during growing up. A woman before and during pregnancy may be dependent on different types of opiates and psychoactive substances. This paper presents the consequences for a mother and child who are pregnant with alcohol, nicotine, heroin, cocaine and marijuana addicts. As a serious negative consequence of drinking alcohol in pregnancy, fetal alcohol syndrome usually occurs. As a consequence of nicotine addiction, there is a sudden infant death syndrome, and as a complication of taking heroin, cocaine and substitution therapy, a newborn apstinence syndrome. Also, the advantages and disadvantages of treatment with substitution therapy in pregnancy, as well as the difference in treatment with methadone and buprenorphine, are presented. In order to ensure the mild availability of treatment by substitution therapy, improve treatment of addiction and stimulate resocialisation of addicts, in 2012 the National Strategy for the Suppression of Drug Abuse in the Republic of Croatia was adopted.