What Is Neonatal Abstinence Syndrome (NAS)?

Medically Reviewed by Dan Brennan, MD on April 22, 2022
Written by Evan Starkman
8 min read

If you’re pregnant and you take certain medications or illegal drugs, they could affect your baby in the womb. The baby could get used to these drugs in its blood over time. After they’re born, they could go through a type of withdrawal called neonatal abstinence syndrome (NAS).

Powerful drugs called opioids often cause NAS. The condition can mean serious symptoms and complications for your baby. Some experts think it may also lead to long-term health problems.

If your baby is born with neonatal abstinence syndrome, treatment can help them get better. You can help your little one recover by giving them plenty of gentle care, too. And if you have a substance use disorder, getting treatment for it can help both you and your child.

When you’re pregnant, almost every drug you take passes from your bloodstream to your baby through your placenta. That’s an organ that forms in your womb during pregnancy. It brings oxygen and nutrients to your baby and gets rid of waste products from their blood.

If you take a drug that affects your nervous system while you’re pregnant, the drug can get into your baby’s blood and affect their nervous system, too. When they stop getting it after they’re born, they could have symptoms of withdrawal.

Opioids during pregnancy are a common cause of neonatal abstinence syndrome. These can be illegal drugs like heroin. They can also be legal prescription painkillers, including:

If opioids cause your baby to get neonatal abstinence syndrome, your doctor may call it neonatal opioid withdrawal syndrome (NOWS).

Some other prescription drugs that can cause NAS are:

  • Antidepressants like selective serotonin reuptake inhibitors (SSRIs)
  • Amphetamines (including stimulants that treat ADHD)
  • Barbiturates (meds that can help someone sleep, ease anxiety and muscle spasms, and stop seizures)
  • Benzodiazepines (sedatives that can ease anxiety and insomnia)

NAS can also be tied to:

Drinking alcohol while you’re pregnant can also make your baby more likely to get a different group of problems that doctors call fetal alcohol spectrum disorders.

The signs aren’t the same for each baby. They can vary based on things like:

  • The type and amount of the drug you took
  • How long you used it, and the last time you took it
  • How your body broke down the drug
  • How far along your pregnancy was when you gave birth

Symptoms of neonatal abstinence syndrome are usually worse if you took more than one drug that affects your central nervous system.

Your baby could start showing symptoms of NAS 1 or 2 days after they’re born. Most infants show signs within about 3 to 5 days. It’s also possible for a baby to get certain symptoms up to 10 days or even a few weeks later.

Your baby could have these symptoms:

  • Shaking or trembling
  • Twitching (overactive reflexes)
  • Tight muscle tone
  • Seizures
  • Fussiness
  • Lots of crying, or crying in a high pitch
  • Sensitive to light, sounds, and touch
  • Feeding or nursing poorly
  • Gaining weight slowly
  • Trouble breathing, including breathing very fast
  • Fever
  • Sweating
  • Blotchy skin
  • Problems sleeping and yawning a lot
  • Diarrhea or vomiting
  • Stuffy nose or sneezing

If your baby was born prematurely, they may be less likely to get NAS symptoms, or they could have symptoms that are less serious. They might recover faster, too, since being born early means they were exposed to less of the drug than a full-term baby.

Along with symptoms of withdrawal, NAS raises your baby’s odds of having:

  • Low birth weight (weighing less than 5 pounds, 8 ounces at birth)
  • Jaundice (a liver condition that causes yellowish skin and eyes)
  • Seizures
  • Sudden infant death syndrome (SIDS), which is when a baby younger than 1 year old dies for no clear reason

That’s unclear. The nonprofit group March of Dimes says we need more research to find out how the syndrome might affect children as they get older. Some experts think NAS could be linked to long-term challenges, including:

  • Not reaching certain milestones (like sitting up, walking, talking, and gaining social and thinking skills) as soon as many other small children do. These delays are also linked to drug exposure in the womb, even if a baby doesn’t get NAS.
  • Problems with bones, muscles, and movement
  • Issues with growth
  • Trouble learning in school and behaving well
  • Problems with speech and language
  • Trouble sleeping
  • Hearing and vision problems
  • Trouble at home, including misusing prescription drugs or taking street drugs

The doctor may use a scoring system to diagnose and grade how serious your baby’s withdrawal is. They assign points based on the symptoms and how serious they are. Then they use the score to figure out the right treatment for your little one.

Some symptoms of NAS can seem like other health problems. So it’s important to give your baby’s doctor an idea of whether your newborn could be at risk for the syndrome. Tell the doctor about:

  • Any medicines you took while pregnant
  • Any street drugs or alcohol you used, including the last time you used them

If you haven’t shared this information with the doctor, they may suspect your baby has NAS based on their symptoms. To be sure, they might test your baby’s urine, their first poop (also called meconium), or the umbilical cord blood or tissue.

A baby with strong withdrawal symptoms, or lots of symptoms, may need to get treatment in a hospital’s newborn intensive care unit (NICU). The right treatment for your baby depends on things like their age, overall health, NAS symptoms, and how serious their neonatal abstinence syndrome is.

The doctor may give them treatments like:

Medications for severe withdrawal. These relieve your baby’s symptoms. They can also help prevent complications like seizures. They may come from the same class or “family” of drugs that the baby was exposed to in the womb. Once your infant’s withdrawal symptoms are under control, the doctor will slowly reduce the amount of medicine to wean your little one off the drug.

Some medicines that can treat serious withdrawal are buprenorphine, methadone, and morphine.

IV fluids through a needle in a vein. These help keep your infant from getting dehydrated, or not having enough water in the body. NAS can bring on dehydration if your baby has diarrhea or throws up a lot.

Higher-calorie baby formula. If your baby has a hard time feeding or if they’re growing slowly, this type of formula can give them the extra calories they need.

Give them plenty of love, and understand that they might be extra grouchy and tough to soothe during treatment. Try these tips to help your baby relax:

Stay in the same room. You can share your baby’s hospital room until they’re healthy enough to go home with you. Keep the room quiet and dimly lit.

Give them skin-to-skin contact. This is also known as “kangaroo care.” When your baby is dressed in a diaper only, place them on your bare chest.

Gently rock your baby. Don’t wake them up if they’re sleeping.

Swaddle them. That means wrap them snuggly in a blanket.

Breastfeed your baby when they’re hungry. It might help ease your baby’s withdrawal symptoms. Ask your doctor and medical team if it’s safe to give your baby breast milk. Also, burp your baby often when you feed them.

Take notes. Keep tabs on how well your baby is eating and sleeping. Also note what things seem to keep them calm.

Give them a pacifier. This could also help soothe your little one.

Most infants who get treatment for neonatal abstinence syndrome get better within 30 days.

Depending on their health, they might need to stay in the hospital anywhere from a few days to weeks or months.

Your baby’s care team at the hospital will let you know when it’s safe to take your little one home. They could give you the OK once your baby:

  • Doesn’t need medicine
  • Eats and sleeps well
  • Is gaining weight
  • Breathes well and has a normal temperature and heart rate
  • Is easy to soothe
  • Has a good score on the test that rates how serious NAS is

Once you bring your infant home, you’ll need to take them to all their recommended follow-up and well-baby checkups. At these visits, your doctor will check your baby for any long-term problems that might be linked to NAS.

If your little one has delays in development (meaning they’re not hitting key milestones on time), ask the doctor to recommend treatments called early intervention services. These can help your child build skills like talking, walking, and socializing. The sooner you get these services, the more helpful they’ll be to your child. The CDC has information on how to find early intervention services near you.

If you’re pregnant or trying to get pregnant and you take any of the medications or street drugs tied to NAS, let your doctor know right away. That’s very important because if you stop taking certain drugs suddenly and without medical supervision, you could have bad health problems and even lose your baby.

In general, tell your pregnancy doctor about any medications or supplements you take, so they can make sure they’re safe for you and your unborn baby. And if you misuse prescription meds or you take street drugs, talk to your doctor about getting into treatment as soon as possible.

If you’re pregnant and you have an opioid use disorder, ask the doctor about medication-assisted treatment (MAT). This type of therapy involves taking prescription medicines like buprenorphine and methadone to help you stop using opioids safely. If you get this treatment and give birth to a baby with NAS, doctors might have an easier time treating your newborn’s withdrawal symptoms.

If you’re pregnant and you see a doctor who prescribes you medicine to treat a health condition, be sure to let the doctor know you’re pregnant. They may take you off certain meds or give you a different type of medicine that’s less risky for your baby’s health. Ask all of your doctors if any medications you take, including prescription drugs, could raise your baby’s chances of getting NAS. Even if you take certain prescription medications exactly as prescribed, it might cause your baby to get NAS.

And if you aren’t pregnant and you take any drug that can lead to NAS, use birth control until you’re ready to conceive safely. Some common ways to prevent pregnancy are the pill, condoms, IUDs (intrauterine devices), and contraceptive implants.