Methadone has been used for treatment of opioid addiction during pregnancy since the 1960s [1,2]. Perinatal methadone substitution therapy provides several potential maternal, obstetrical, and neonatal benefits (table 1). For example, a stable methadone dose reduces stress on the fetus from repeated withdrawal due to inconsistent availability of illicit drugs. Additional benefits include a potential reduction in drug-seeking behaviors, including trading sex for drugs and in engaging in commercial sex to obtain money to buy drugs. Pregnant women enrolled in a substance use disorders treatment program are more likely to receive prenatal care, have infants of higher birth weight and be discharged home with their neonate [3-6]. Nevertheless, there are several barriers to methadone treatment, including lack of insurance, incarceration, transportation and childcare needs, guilt about the effect of drugs on the fetus, and fear of legal consequences, including loss of custody of children.
This topic will review management of methadone maintenance therapy in pregnant women. Issues relating to detection and consequences of substance use in pregnancy are discussed separately. (See "Overview of illicit drug use in pregnant women".)
METHADONE MAINTENANCE THERAPY VERSUS DETOXIFICATION
The two main approaches to treatment of opioid addiction during pregnancy are methadone maintenance therapy and detoxification (see 'Detoxification' below). Both approaches require substitution of methadone for illicit opioids.
The goal of maintenance therapy is administration of methadone in doses sufficient to prevent symptoms of withdrawal and reduce or eliminate drug craving. Detoxification, on the other hand, aims to lower the maternal methadone dose to achieve the lowest possible dose that prevents withdrawal symptoms and ultimately to eliminate methadone use. Proponents of detoxification cite evidence that lower doses of methadone reduce neonatal sequelae of maternal opioid use [7-13]. The major disadvantage of detoxification is that a high proportion of women return to illicit opioid use [7,14]. These two treatment modalities have never been compared in a randomized trial involving pregnant women. Methadone maintenance therapy is considered the standard of care for pregnant women dependent on opioids [15,16]. Buprenorphine substitution therapy is becoming an alternative to methadone maintenance therapy. (See "Buprenorphine substitution therapy in pregnancy".)
CANDIDATES FOR METHADONE TREATMENT
Regulations regarding methadone use vary by state and/or country . In general, pregnant women who are physiologically dependent on heroin, "street methadone," or other opioids are potential candidates for methadone treatment. Methadone may also be a reasonable option for management of chronic pain, such as low back pain, during pregnancy, but this indication is beyond the scope of this topic .