Understanding Neonatal Abstinence Syndrome (NAS)

Neonatal abstinence syndrome (NAS) is a problem that can happen to a baby exposed to drugs in the womb. It’s a set of signs and symptoms that happen to a baby when the birth mother has used opioid medicines or drugs in pregnancy. The baby then has drug withdrawal after birth. 

What causes NAS?

Most drugs and medicines that a mother takes pass from her bloodstream to her unborn baby. Some are more likely to cause NAS than others. They include:

  • Opioid drugs such as heroin

  • Opioid medicines such as codeine and oxycodone

  • Medicines such as buprenorphine or methadone that are used to treat opioid use disorder

  • Products of a type of plant called kratom

  • Medicines to treat depression, such as fluoxetine, sertraline, or citalopram

  • Nicotine from tobacco use

Alcohol use can also cause a different set of problems. These are called fetal alcohol spectrum disorders (FASD).

Signs of NAS

Signs of withdrawal may start 24 to 48 hours after birth. Or they may start as late as 5 to 10 days after birth. The timing depends on the drug or medicine. The signs in a full-term baby may include:

  • Trembling

  • Too much crying or high-pitched crying

  • Sleep problems

  • Tight muscle tone

  • Overactive reflexes

  • Seizures

  • Yawning, stuffy nose, and sneezing

  • Poor feeding or trouble sucking

  • Vomiting or diarrhea

  • Sweating

  • Fever or unstable temperature

A preterm baby may have signs that are less severe. They may get better faster. This may be because their nervous system is less mature. Or it may be because they were exposed to less drugs than a full-term baby.

Diagnosing NAS

The healthcare provider will ask about your medicine or substance use. The more information you can give will help your baby. Be as accurate and detailed as you can. Note the time you last took the medicine or drug.

The healthcare provider may use a scoring system for your baby. This is to keep track of how severe their withdrawal is. This scoring may help to plan treatment. The healthcare provider may check your baby’s meconium, urine, and umbilical cord tissue. Some birth centers routinely screen all babies.

Treatment for NAS

Treatment will depend on how severe your baby's symptoms are, your baby's age, and their general health. Treatment decisions may be based on your baby's ability to eat, sleep, and be consoled. This is called ESC.  

You are an important part of your baby’s recovery. A baby with withdrawal is fussy and unhappy. They may be hard to comfort. Wrapping your baby snugly in a blanket may help give comfort. Your baby may also need extra calories added to feedings. This is because crying and fussing uses more energy.

Your baby may need IV fluids if they are dehydrated or have severe vomiting or diarrhea. Some babies may need medicines. These can prevent severe problems such as seizures. Medicines may help ease the discomfort of withdrawal. If medicine is needed, your baby will likely be given a medicine that is in the same family of drugs as the one causing withdrawal. Once the signs of withdrawal are under control, the amount of the medicine is slowly decreased. This helps wean your baby off the drug.

Your baby's healthcare provider will talk with you about which treatments might work best for your baby.

Possible complications of NAS

Other problems may include:

  • Poor growth in the womb

  • Being born too soon

  • Seizures

  • Birth defects

Even without NAS, prenatal drug contact is linked to later developmental delay. Some drugs have been linked to specific problems. These include:

  • Opioids. These can cause serious withdrawal in the baby. Some signs can last as long as 4 to 6 months. Seizures may also occur in babies born to opioid users.

  • Amphetamines. These can lead to low birth weight and preterm birth.

  • Cocaine. This can cause poor growth. It also makes problems such as placental abruption more likely.

  • Marijuana. This may cause lower birth weight. It may also cause later problems with learning and behavior.

  • Alcohol. This can have major effects on babies before and after birth. It can slow growth during pregnancy and after birth. It can also cause problems of the head and face, heart defects, learning problems, and mental problems.

  • Cigarette smoking. This may cause low birth weight. It may also put babies at higher risk for preterm birth and stillbirth.

When to call the healthcare provider

Call the healthcare provider if your baby has any of these:

  • Signs that don’t get better, or that get worse

  • New signs

© 2000-2024 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.
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