Neonatal abstinence syndrome (NAS) happens when your baby withdraws from substances that reached them in the womb, most often opioids. Even prescribed methadone or buprenorphine can cause it. After birth, the supply stops abruptly, and your baby may show irritability, tremors, feeding trouble, or poor sleep. Not every exposed baby develops NAS, and it’s very treatable. Next, you’ll learn what causes it, how hospital care teams treat it, and why treatment during pregnancy still matters.
Key Takeaways
- Neonatal abstinence syndrome is withdrawal in newborns after prenatal exposure to substances, most commonly opioids, including prescribed medications like methadone or buprenorphine.
- Substances cross the placenta, so the baby adapts to them; when the supply stops abruptly at birth, withdrawal signs can follow.
- Symptoms include excessive crying, tremors, stiff muscles, poor sleep, feeding problems, vomiting, diarrhea, sweating, fever, and, in severe cases, seizures.
- Diagnosis relies on prenatal exposure history and monitoring every 3, 4 hours, often using the Finnegan Neonatal Abstinence Scoring Tool.
- Treatment starts with swaddling, quiet dim rooms, rooming-in, and frequent small feeds; severe cases may require tapered oral morphine or methadone.
What is neonatal abstinence syndrome (NAS)
Neonatal abstinence syndrome (NAS) describes a range of withdrawal signs your baby may show after exposure to certain substances before birth. A newborn can experience withdrawal much like an adult can. When opioids cause these signs, clinicians call it neonatal opioid withdrawal syndrome (NOWS), a subset of NAS focused on the first 28 days after birth.
Exposure can come from prescribed or nonprescribed opioids, or from medications that treat opioid use disorder, such as methadone or buprenorphine. You may notice effects on your baby’s nervous system, body regulation, and digestion.
Exposure doesn’t guarantee withdrawal. Whether your baby develops symptoms, and how severe they become, depends on the substance, your baby’s health, and gestational age. Withdrawal ranges from mild to severe, and rare cases can be life-threatening.
What causes NAS (opioids, benzos, and other substances)
NAS is caused by exposure to certain substances in the womb, most commonly opioids, along with benzodiazepines and other sedatives. These substances cross the placenta, and your baby’s body can adapt to them. After birth, that supply stops abruptly, and withdrawal signs can follow.
Substances like opioids cross the placenta, and your baby’s body can adapt to them. When that supply stops at birth, withdrawal can follow.
Opioids are a common, well-documented cause, and this opioid-specific form is called neonatal opioid withdrawal syndrome (NOWS). Exposure can involve prescribed or nonprescribed opioids, as well as methadone or buprenorphine used to treat opioid use disorder.
Other substances, including sedatives such as benzodiazepines, can also contribute to NAS.
Exposure doesn’t guarantee withdrawal. ACOG reports NAS in roughly 30, 80% of infants whose mothers receive opioid agonist therapy. Your baby’s risk and severity depend on the specific substances involved, overall newborn health, and gestational age. Your clinicians can assess these factors.
What the symptoms of NAS look like in a newborn
NAS symptoms in a newborn include excessive crying, irritability, tremors, stiff or tense muscles, and trouble sleeping. These signs appear because withdrawal affects your baby’s central nervous system, autonomic regulation, and digestive system.
Your baby may also struggle to feed, vomit, have diarrhea, or gain weight poorly. Sweating, fever, and unstable body temperature can also occur, and severe withdrawal can cause seizures.
Timing depends on the substance. Heroin withdrawal often starts within 24 hours. Methadone-related signs usually appear within 48, 72 hours and sometimes later. If your baby was exposed to buprenorphine, signs typically emerge within 12, 48 hours and can peak at 72, 96 hours.
Exposure doesn’t guarantee withdrawal, and severity varies. Because these signs can resemble infection, your baby’s care team evaluates them carefully.
How NAS is diagnosed and treated in the hospital
In the hospital, NAS is diagnosed using your history of substance or medication exposure during pregnancy and careful observation of your baby after birth, and it is treated with supportive care, adding medication if severe symptoms persist. Your care team may use a standardized tool, such as the Finnegan Neonatal Abstinence Scoring Tool, to measure withdrawal signs every 3, 4 hours. Because these signs can resemble infection, seizures, or breathing problems, clinicians also rule out other conditions.
Supportive care comes first. You can help by keeping your baby in a quiet, dim room, swaddling, gently soothing, rooming-in, and offering frequent small feeds. If severe symptoms persist, clinicians may give oral morphine or methadone and taper the dose as your baby improves. Expect monitoring for 4, 7 days without medication, or 24, 48 hours after medication stops.
How NAS severity compares by substance
NAS severity varies by substance: the substance your baby was exposed to before birth helps shape whether withdrawal develops, how severe it becomes, and when it starts. Every exposed baby still responds differently.
| Substance | Typical onset | What to know |
|---|---|---|
| Heroin | Within 24 hours | Signs often appear early |
| Methadone | 48, 72 hours | Signs can be delayed |
| Buprenorphine | 12, 48 hours | Signs may peak at 72, 96 hours |
| Non-opioid drugs | Varies | NOWS refers only to opioids |
Severity also depends on your baby’s gestational age, overall health, and other substances involved. Tell your care team about every exposure so they can monitor accurately and respond quickly.
Why treatment during pregnancy reduces NAS risk
Treatment with methadone or buprenorphine during pregnancy lowers your baby’s risk by replacing unpredictability with structure, which protects you both. It doesn’t eliminate NAS. ACOG reports withdrawal in roughly 30, 80% of infants whose mothers receive opioid agonist therapy. The structure helps in these ways:
- Your baby’s exposure comes from a known, prescribed dose rather than unknown nonprescribed substances.
- Your care team knows the medication, so they can anticipate when signs may appear.
- Coordinated prenatal and pediatric care means clinicians watch your baby closely from birth.
- Steady treatment helps you stay present for rooming-in, swaddling, and feeding, the comfort your baby needs.
Talk with your clinicians about individualized planning.
How Simonds Recovery Centers supports people seeking help during pregnancy
Simonds Recovery Centers supports people seeking help during pregnancy by offering compassionate, judgment-free care focused on your health and your pregnancy. If you’re pregnant and using opioids, reaching out for help is one of the most protective steps you can take for yourself and your baby. Our team can help you understand evidence-based treatment options for opioid use disorder, including medications such as methadone or buprenorphine, and why stopping opioids abruptly isn’t recommended without medical guidance. We’ll work with you to coordinate care between your prenatal providers and your baby’s future pediatric team, so everyone shares one plan. You’ll also learn what to expect after birth, including monitoring for withdrawal and soothing measures like rooming-in and swaddling. Your treatment plan is individualized, because your needs matter. Reach out today.
Keep Opioid Treatment Going
If you are pregnant and receiving treatment for opioid use disorder, staying in care through pregnancy and after delivery can help support your recovery and reduce overdose risk. Simonds Recovery provides medication-assisted treatment with ongoing support for opioid use disorder.
Call (833) 781-8338 to discuss treatment and continuing care.
Frequently Asked Questions
Can I Breastfeed My Baby if I’m Taking Methadone or Buprenorphine?
Often, yes. Methadone or buprenorphine treatment does not by itself prevent breastfeeding, and breastfeeding may provide benefits for babies experiencing neonatal opioid withdrawal syndrome. Your care team will consider factors such as your treatment stability, use of other substances, medications, and your baby’s health. Follow your obstetric and pediatric providers’ recommendations, and do not stop your medication to breastfeed.
How Long Will My Baby Need to Stay in the Hospital After Birth?
There is no single hospital stay that applies to every baby exposed to opioids. Observation time depends on the opioid involved, timing of the last exposure, the baby’s symptoms, feeding and weight gain, and whether medication treatment is needed. Babies who require medication generally remain hospitalized longer for treatment and observation after medication is stopped. Your newborn’s care team can explain the monitoring period based on the specific exposure.
Does NAS Cause Long-Term Developmental or Learning Problems as Children Grow?
Prenatal opioid exposure has been associated with potential developmental, behavioral, and learning differences, but neonatal withdrawal itself does not determine a child’s long-term outcome. Many factors can influence development, including genetics, environment, prenatal health, and exposure to other substances. Regular pediatric visits and developmental screening can help identify concerns early and connect your child with appropriate support.
How Can Parents Soothe a Baby With Withdrawal Symptoms at Home?
Keep the environment calm, reduce excessive noise and bright light, and use gentle holding, rocking, and swaddling when recommended by your baby’s care team. Feeding support and frequent smaller feeds may also help some babies. Follow the discharge instructions provided by the hospital, and contact your pediatrician if feeding becomes difficult, your baby is not gaining weight, has signs of dehydration, or develops concerning symptoms such as a seizure.
Will Child Protective Services Get Involved if My Baby Has NAS?
It depends on the state, the circumstances of the substance exposure, and applicable reporting laws. Some states require healthcare providers to notify child welfare agencies or develop a plan of safe care when a newborn has been exposed to substances. A notification does not automatically mean that a baby will be removed from the parent. Ask your hospital’s social worker or care team how the rules apply in your state and situation.
