Pharmacotherapy for pregnant patients with OUD, Opioid Use Disorder. Methadone, a full agonist of the u-opioid receptor is used as standard treatment in MAW, Medication Assisted Withdrawal. Illustration shows taking a daily dose of methadone, which is transported across the placental barrier. Neonatal Abstinence Syndrome is experienced by infants exposed to opioids illicit or described. Postnatal withdrawal syndrome is considered less severe for infants exposed to medication assisted therapy.