Neonatal abstinence syndrome (NAS) is a group of problems that occurs in a newborn who was exposed to opioid drugs for a length of time while in the mother’s womb.
Originally, this syndrome referred to infants born to mothers who used opioids during pregnancy, but today the term has been broadened to include infants whose mothers have used or abused other psychoactive substances during pregnancy that produce the same symptoms.
NAS may occur when a pregnant woman takes drugs such as heroin, codeine, oxycodone (Oxycontin), methadone, or buprenorphine.
These and other substances pass through the placenta that connects the baby to its mother in the womb. The baby becomes dependent on the drug along with the mother.
If the mother continues to use the drugs within the week or so before delivery, the baby will be dependent on the drug at birth. Because the baby is no longer getting the drug after birth, withdrawal symptoms may occur as the drug is slowly cleared from the baby’s system.
Withdrawal symptoms also may occur in babies exposed to alcohol, benzodiazepines, barbiturates, and certain antidepressants (SSRIs) while in the womb.
Babies of mothers who use opioids and other addictive drugs (nicotine, amphetamines, cocaine, marijuana, alcohol) may have long-term problems. While there is no clear evidence of a NAS for other drugs, they may contribute to the severity of a baby’s NAS symptoms.