Neonatal abstinence syndrome (NAS)


  • NAS can cause serious problems for your baby, like being born too small and having breathing problems.

  • If you’re pregnant and taking opioids, talk to your provider before you stop taking them. Stopping opioids too quickly can harm you and your baby.

  • Even if you use an opioid exactly as your health care provider tells you to, it may cause NAS in your baby.

  • Tell your prenatal care provider about any opioid you take, even if it’s prescribed to you by another health care provider. 

  • If you’re not pregnant and you’re using opioids, use birth control until you’re ready to get pregnant. This can help prevent NAS in your baby.

Neonatal abstinence syndrome (also called NAS) happens when a baby is exposed to drugs in the womb before birth. A baby can then go through drug withdrawal after birth. 

NAS most often is caused when a woman takes opioids during pregnancy. Opioids are painkillers (used to relieve pain) your provider may prescribe if you’ve been injured or had surgery. Prescription opioids include: 

  • Codeine and hydrocodone (Vicodin®)
  • Morphine (Kadian®, Avinza®) 
  • Oxycodone (OxyContin®, Percocet®)

The street drug heroin also is an opioid. When you take these kinds of drugs during pregnancy, they can pass through the placenta and cause serious problems for your baby. The placenta grows in your uterus (womb) and supplies your baby with food and oxygen through the umbilical cord.

Can using other drugs lead to neonatal abstinence syndrome in your baby?

Yes. In addition to opioids, using these drugs during pregnancy can lead to NAS in your baby: 

  • Antidepressants (prescription drugs used to treat depression) 
  • Benzodiazepines (sleeping pills)

What problems can neonatal abstinence syndrome cause in your baby?

Babies with NAS are more likely than other babies to be born with low birthweight (less than 5 pounds, 8 ounces), have breathing and feeding problems and seizures. They usually have to stay in the hospital longer after birth than babies without NAS. 

Taking opioids and other drugs during pregnancy can cause your baby to be born with birth defects. A birth defect is a health condition that is present at birth. Birth defects can change the shape or function of one or more parts of the body. They can cause problems in overall health, how the body develops, or in how the body works.

What can you do to help prevent NAS in your baby?

If you’re pregnant and you use any of the drugs that can cause NAS, tell your health care provider right away. But don’t stop taking the drug without getting treatment from your provider first. Quitting suddenly (sometimes called cold turkey) can cause severe problems for your baby, including death. If you need help to stop using these drugs, talk to your provider about treatment to help you quit. Getting treatment can help you stop using drugs and is safer for your baby than getting no treatment at all. 

If you’re addicted to opioids, medication-assisted treatment (also called MAT) during pregnancy can help your baby. NAS in babies may be easier to treat for babies whose moms get MAT during pregnancy. Medicines used in MAT include methadone and buprenorphine.

Even if you use a prescription drug exactly as your provider tells you to, it may cause NAS in your baby. During pregnancy, tell your prenatal care provider about any drug or medicine you take. If you go to a health care provider who prescribes medicine to treat a health condition (like sleep problems or severe pain), make sure that provider knows you’re pregnant. You may need to stop taking certain medicines or change to medicine that’s safer for your baby. Ask all your health care providers if the drugs you take—even prescription drugs—can cause NAS in your baby.

If you’re not pregnant and using any of the drugs that can cause NAS, use birth control until you’re ready to get pregnant. Birth control (also called contraception or family planning) is methods you use to keep from getting pregnant.

If you’re pregnant or thinking about getting pregnant, tell your health care provider right away about any drug or medicine you take. She can make sure that what you’re taking is safe for you and your baby. She also can help you get treatment for using street drugs or abusing prescription drugs if you need it. If you abuse prescription drugs, it means you take more than has been prescribed for you, you take someone else’s prescription drug, or you get the drug from someone without a prescription. 

If you’re not pregnant, quit using street drugs or abusing prescription drugs before you get pregnant. This is the best way to prevent NAS. 

What are signs and symptoms of NAS?

Signs and symptoms can be different for every baby with NAS. Most appear within 3 days (72 hours) of birth, but some can appear right after birth or within a few weeks of birth. Signs and symptoms can include: 

  • Body shakes (tremors), seizures (convulsions), overactive reflexes (twitching) and tight muscle tone
  • Fussiness, excessive crying or having a high-pitched cry
  • Poor feeding, poor sucking or slow weight gain
  • Breathing really fast
  • Fever, sweating or blotchy skin
  • Trouble sleeping and lots of yawning
  • Diarrhea or throwing up
  • Stuffy nose or sneezing

Call your baby’s health care provider if your baby has any of these symptoms. Not all babies with NAS have the same symptoms. Symptoms depend on: 

  • What drug you used during pregnancy, how much you used and how long you took it
  • How your own body breaks down the drug
  • If your baby was born prematurely (before 37 weeks of pregnancy) 

NAS can last from 1 week to 6 months after birth.

How is your baby tested for NAS?

Your baby’s provider can use these tests to see if he has NAS:

  • Neonatal abstinence scoring system. This system gives points for each NAS symptom depending on how severe it is. Your baby’s provider uses the score to decide what kind of treatment your baby needs.  
  • Test of your baby’s first bowel movements (also called meconium) 
  • Test of your baby’s urine 

How is NAS treated?

Your baby’s treatment may include:

  • Taking medicines to treat or manage severe withdrawal symptoms. Your baby’s provider may give her a medicine that’s similar to the drug you used during pregnancy. This can help relieve your baby’s withdrawal symptoms. Once these symptoms are under control, your baby gets smaller doses of the medicine over time so her body can adjust to being off the medicine. Medicines used to treat severe withdrawal symptoms include morphine, methadone and buprenorphine. 
  • Getting fluids through a needle into a vein (also called intravenous or IV). Babies with NAS can get very dehydrated from having diarrhea or throwing up a lot. If a baby’s dehydrated, she doesn’t have enough water in her body. Getting fluids through an IV helps keep your baby from getting dehydrated.
  • Drinking higher-calorie baby formula. Some babies with NAS need extra calories to help them grow because they have trouble feeding or slow growth.

Most babies with NAS who get treatment get better in 5 to 30 days. 

While your baby’s being treated for NAS, he may be fussy and hard to soothe. Doing these things can help calm him: 

  • Swaddle your baby in a blanket.
  • Give your baby skin-to-skin care (also called kangaroo care). It’s when you put your baby, dressed only in a diaper, on your bare chest. 
  • Keep your baby in a quiet, dimly lit room.
  • Breastfeed your baby.

More information

See also: Prescription opioids during pregnancy

Last reviewed: April, 2015