Neonatal Abstinence Syndrome

aBRee CoWan, PhaRmD CanDIDate 2023; jamIe l. mCConaha, PhaRmD, nCttP, BCaCP, CDCes

What is Neonatal Abstinence Syndrome

Neonatal abstinence syndrome (NAS) is characterized by symptoms of withdrawal in the neonate after chronic intrauterine exposure to a substance(s) near or at the time of delivery.1 The neonate is physically dependent on the substance(s) but not addicted. Withdrawal symptoms begin shortly after delivery due to the abrupt cessation of the substance at birth. Neonatal opioid withdrawal syndrome (NOWS) is the specific subset of withdrawal associated with maternal opioid use disorder.

Short- and Long-Term Effects of Neonatal Opioid Exposure

Opioid exposure in the neonate can have serious side effects. Exposed neonates are at higher risk of low birth weight, small head circumference and premature birth. Although more research on the long-term effects of neonatal abstinence (NAS) or neonatal opioid withdrawal syndrome (NOWS) is needed, it is suspected to negatively impact hearing, vision, and cause problems with learning and overall behavior.6

Due to the suspected long-term effects of opioid exposure and withdrawal in the neonate, close monitoring and follow-up should be done. After discharge, the neonate should be referred to a center or program that offers comprehensive care and services. Close monitoring of developmental, behavioral, and mental health status of the neonate after discharge is crucial.5

Substances of Abuse

There are multiple different substances of abuse that can cause neonates to experience withdrawal symptoms. Marijuana is commonly used but is not associated with withdrawal symptoms in the neonate. Similarly, cocaine does not cause a physical dependence, but when used in conjunction with other substances, like opioids, it can potentiate symptoms of withdrawal. When benzodiazepines and opioids are used during pregnancy, withdrawal symptoms may occur in the neonate.

Neonatal abstinence syndrome is not always a result of illicit drug use during pregnancy, it can also occur due to treatment of chronic disease states of the mother. When someone on chronic opioid therapy becomes pregnant, there are safe and evidence based alternative therapies for disease state management. The two literature supported alternatives for the pregnant population are methadone and buprenorphine.

Methadone, a full µ-opioid receptor agonist, is available through federally licensed opioid treatment programs. Buprenorphine, is a partial µ-opioid receptor antagonist and partial µ-opioid receptor agonist. Due to the Drug Addiction Treatment Act of 2000, buprenorphine is available through a prescriber that has obtained the appropriate waiver. Similar to methadone, it is also available through federally licensed opioid treatment programs.

Prevalence of Maternal Substance Abuse in the United States

Maternal substance abuse in the United States leads to increased rates of maternal morbidity.3 Substance abuse also increases risk of negative health outcomes of the infant, such as still birth. It is estimated that about five percent of the pregnant population uses one or more addictive substances9. With the increased risks of negative maternal and neonatal side effects due to substance abuse, it is important to be aware of what substances can be abused, maternal and neonatal screening options as well as symptoms of withdrawal in the neonate.

Prevalence of Neonatal Abstinence Syndrome and Opioid Use Disorder in Allegheny County

The opioid epidemic affects the entire state of Pennsylvania but is more prominent in certain counties than others. In 2020, the annual rate of maternal opioid use disorder (OUD) diagnosis at delivery was 17.37 out of every 1,000 births in Allegheny County.2 During that same year in Allegheny County, 48.91 out of 1,000 births resulted in neonatal abstinence syndrome.2 Rates in rural counties tend to be higher than in urban areas.