What Is Neonatal Abstinence Syndrome?

Neonatal Abstinence Syndrome (NAS) refers to a group of behavioral and physical conditions a baby experiences when withdrawing from exposure to drugs in the womb. There are two major types of NAS: prenatal NAS due to maternal substance use that results in withdrawal symptoms in the newborn and postnatal NAS due to discontinuation of medications such as fentanyl or morphine which are used for pain therapy in newborns admitted to the neonatal intensive care unit (NICU).

Prenatal NAS is more common and is the leading preventable cause of mental, physical, and psychological problems in infants and children. This type of NAS is typically caused by maternal opioid use. When a mother takes these drugs during pregnancy, they can pass through the placenta to the fetus. The placenta supplies the fetus with food and oxygen through the umbilical cord and will transfer to the fetus drugs the mother takes as well. Once born, babies may be dependent on the drugs they were exposed to in the womb and suffer from withdrawal symptoms.

Substance use by pregnant women has both medical and developmental consequences for the newborn in addition to legal, health, and economic consequences for the mother.

What Drugs Cause Neonatal Abstinence Syndrome?

Opiates such as heroin and methadone cause over half of the NAS withdrawal symptoms in babies that are exposed to drugs prenatally. While NAS is most often caused by the mother taking opioid drugs during pregnancy, it can result from the use of multiple medications and substances. Withdrawal symptoms may also occur in babies exposed to cocaine, benzodiazepines, barbiturates, and certain antidepressants (SSRIs) while in the womb. Additionally, alcohol use can cause withdrawal in newborns as well as a group of problems called fetal alcohol spectrum disorders (FASDs).

Signs And Symptoms Of Neonatal Abstinence Syndrome

The signs of NAS can differ for every baby. Although time estimates are different for each substance, most NAS symptoms last for about 7 to 10 days; however, some symptoms can persist for up to 6 months after birth. Common signs of NAS include the following neurological, metabolic, respiratory, and gastrointestinal symptoms:

Neurological Excitability

  • Agitation and restlessness
  • Hyper-irritability
  • High-pitched and excessive crying
  • Sleeping difficulties
  • Tremors and possible seizures

Metabolic And Respiratory Disturbance

  • Irregular body temperature
  • Excessive sweating
  • Fever and blotchy skin
  • Nasal flaring, stuffiness, and sneezing
  • Excessive yawning
  • Problems breathing

Gastrointestinal Dysfunction

  • Diarrhea
  • Vomiting
  • Poor feeding
  • Dehydration
  • Excessive sucking
  • Slow weight gain

In addition to these symptoms, NAS can also cause complications such as low birth-weight and jaundice. These conditions are indicative of developmental difficulties that often need to be treated with medication under the supervision of medical professionals.

Neonatal Abstinence Syndrome Diagnosis

There are a few tests that medical providers will use to see if a newborn has NAS, including the following:

  • Neonatal Abstinence Scoring System: Standardized system that gives points for each NAS symptom present in the baby in order to form a treatment plan.
  • Meconium Test: Evaluation of the baby’s first bowel movement.
  • Urinalysis Assessment: Examination of the baby’s urine.

Scoring Neonatal Abstinence Syndrome

Using a NAS scoring system allows clinicians to diagnose the severity of each case and develop appropriate treatment plans for each infant. The most widely used standardized scoring tool is the Finnegan Neonatal Abstinence Scoring System. The Finnegan System assigns points to specific signs and symptoms that are tracked over a 7 day period. Medical professionals typically begin scoring around 24 hours after birth and monitor symptoms every 3 to 4 hours to adjust the score as needed. This scoring helps determine the baby’s treatment plan while in the NICU as well as necessary follow-up care for the mother and baby after they are discharged from the hospital.

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Neonatal Abstinence Syndrome Treatment

Common treatments for babies diagnosed with NAS include:

  • Taking medications to treat or manage withdrawal symptoms. Babies with NAS may experience severe symptoms, such as seizures, that require medicine. Common medications used to treat severe NAS withdrawal include morphine, methadone, and buprenorphine.
  • Receiving intravenous fluids to prevent the baby from becoming dehydrated. Babies with NAS typically get dehydrated from excessive diarrhea or vomiting.
  • Drinking higher calorie baby formula. Babies with NAS often need extra calories due to their increased activity and trouble feeding.

Most babies that receive treatment recover from the initial effects of NAS in about 5 to 30 days. However, the long-term effects of substance abuse can last for years.

Neonatal Abstinence Syndrome Statistics



Every 15 minutes, a baby is born addicted to opioid drugs in the United States.



Nearly 50-75% of infants exposed to opioids in utero require medical assistance.



The number of babies born addicted to opioids in the US has tripled within the last 15 years.

Get Help And Prevent Neonatal Abstinence Syndrome Today

NAS may be easier to treat when mothers get medication-assisted treatment (MAT) during pregnancy. MAT can ensure expecting mothers a safe detox process and a nurturing environment that focuses on healing. For new mothers and their babies, ending the drug use that caused NAS is imperative to a healthy future. If you’re someone that may become pregnant and are struggling with an addiction, contact a treatment provider to find a rehab program today.