Neonatal Abstinence Syndrome (NAS) in Newborns: Causes, Symptoms, and Treatment

Neonatal Abstinence Syndrome (NAS) is a condition that affects newborn babies who have been exposed to addictive drugs in the womb. After birth, when the umbilical cord is cut and drug supply stops abruptly, these infants go through withdrawal symptoms that can be painful and even life-threatening if not managed properly.

The rise in prescription opioid use, heroin, and other substance abuse among pregnant women has led to a significant increase in NAS cases globally. Understanding this condition is not only vital for healthcare providers but also for expecting mothers, caregivers, and policymakers.

This article offers a detailed and compassionate overview of Neonatal Abstinence Syndrome, including its causes, signs, diagnosis, treatment strategies, and long-term outcomes. We also explore SEO-relevant terms such as “drug withdrawal in newborns,” “opioid withdrawal in infants,” “newborns exposed to drugs in utero,” and “treatment for neonatal abstinence syndrome” to support awareness and digital health literacy.

What is Neonatal Abstinence Syndrome?

Neonatal Abstinence Syndrome (NAS) refers to a group of conditions caused when a newborn withdraws from certain drugs, most commonly opioids, that were used by the mother during pregnancy. These substances cross the placenta and affect the baby’s developing nervous system. When the baby is born and the drug supply suddenly stops, withdrawal begins—usually within the first 24–72 hours.

NAS is especially linked to opioid use, including medications like morphine, codeine, methadone, buprenorphine, and heroin. However, other drugs like benzodiazepines, barbiturates, SSRIs (antidepressants), alcohol, and nicotine can also contribute.

Causes of Neonatal Abstinence Syndrome

How Does NAS Develop?

NAS occurs when a pregnant woman uses addictive substances that pass through the placenta to the fetus. The baby becomes dependent on the drug, just like the mother. After delivery, the sudden halt in exposure triggers withdrawal symptoms in the newborn.

Substances most commonly linked to NAS include:

• Prescription opioids (e.g., oxycodone, hydrocodone)
• Methadone or buprenorphine used in medication-assisted treatment
• Heroin
• Benzodiazepines (e.g., diazepam, lorazepam)
• Cocaine
• Nicotine and alcohol

The risk and severity of NAS depend on several factors:

• Type of drug used
• Duration and frequency of use
• Time of last use before delivery
• Use of multiple substances (poly-drug exposure)
• Infant’s gestational age and genetic susceptibility

Symptoms of Neonatal Abstinence Syndrome

What Does Drug Withdrawal Look Like in a Newborn?

The symptoms of neonatal drug withdrawal can vary depending on the substance involved, the duration of exposure, and the baby’s individual metabolism. Symptoms typically begin within 1–3 days after birth, but in some cases, especially with long-acting opioids like methadone, they may take up to a week.

Common signs include:

• High-pitched crying
• Irritability or excessive fussiness
• Tremors or jitteriness
• Poor feeding or vomiting
• Sweating and fever
• Frequent yawning or sneezing
• Sleep disturbances
• Rapid breathing
• Stuffy nose
• Diarrhea and diaper rash
• Seizures (in severe cases)

These symptoms are scored using tools like the Finnegan Neonatal Abstinence Scoring System, which helps guide treatment decisions.

Diagnosis of Neonatal Abstinence Syndrome

Clinical and Laboratory Assessment

The diagnosis of NAS is primarily clinical, based on the observation of withdrawal symptoms and a detailed maternal history. Additional tools and tests include:

• Finnegan Score: Assesses severity based on symptoms
• Urine or meconium toxicology screening: Detects recent drug exposure
• Cord blood or hair testing: For longer-term exposure
• Maternal interview and medical history

It is crucial to approach diagnosis with compassion and privacy, ensuring that mothers are not stigmatized but supported.

Treatment of Neonatal Abstinence Syndrome

Supportive and Pharmacologic Care

Treatment of NAS in newborns involves both non-pharmacological and medication-based approaches depending on the severity of withdrawal.

Non-Pharmacological Care (First-line for all babies)

• Rooming-in with the mother to promote bonding and breastfeeding (if safe)
• Swaddling and gentle rocking to soothe the baby
• Minimizing environmental stimuli (noise, bright lights)
• Skin-to-skin contact
• Frequent, small feedings with high-calorie formula or expressed breast milk

Pharmacologic Treatment

When symptoms are moderate to severe, medications may be used:

• Morphine or methadone: To relieve opioid withdrawal symptoms
• Phenobarbital or clonidine: For severe or multi-drug exposure

Doses are carefully tapered based on symptom improvement.

Hospital Stay and Monitoring

Babies with NAS often require prolonged hospital stays, averaging 2–4 weeks. During this time, they are monitored for:

• Weight gain
• Hydration and feeding ability
• Neurological stability
• Risk of seizures or apnea

Long-Term Effects and Prognosis

What to Expect After Discharge

Most babies with NAS recover well with appropriate care. However, studies show that exposed infants may have higher risks of:

• Developmental delays
• Behavioral issues
• Sleep disturbances
• Attention-deficit/hyperactivity disorder (ADHD)
• Learning difficulties in school-age years

These effects are more likely when there’s continued substance exposure, poor postnatal environment, or lack of early intervention.

Ongoing developmental monitoring, early intervention services, and parental support are critical to improving outcomes.

Prevention of Neonatal Abstinence Syndrome

Education, Support, and Medical Supervision

Preventing NAS requires addressing substance use before and during pregnancy. Key prevention strategies include:

• Preconception counseling
• Medication-assisted treatment (MAT) for opioid use disorder
• Mental health and behavioral therapy
• Smoking and alcohol cessation support
• Prenatal care and routine screening for substance use
• Non-stigmatizing, compassionate care for expectant mothers

Community programs, public health efforts, and awareness campaigns are essential to reduce the incidence of NAS and support maternal-child health.

Table: Opioid vs Non-Opioid NAS Characteristics

Frequently Asked Questions (FAQs)

What is Neonatal Abstinence Syndrome and why does it occur?

Neonatal Abstinence Syndrome (NAS) is a condition seen in newborns who were exposed to addictive substances in the womb and experience withdrawal after birth. It happens because drugs like opioids, when used during pregnancy, pass through the placenta to the fetus. The baby’s developing body becomes dependent on the substance. Once the baby is born and the drug supply is abruptly stopped, the baby’s nervous system reacts, leading to symptoms like irritability, poor feeding, tremors, and excessive crying. NAS is most commonly linked to opioids but can also occur with other drugs like benzodiazepines, antidepressants, alcohol, and nicotine.

What are the first signs that a baby has NAS?

The symptoms of NAS can start as early as 24 hours after birth, especially if short-acting opioids like heroin are involved. Initial signs include excessive crying, irritability, tremors, poor feeding, and trouble sleeping. Babies may also develop vomiting, diarrhea, and weight loss. In more severe cases, they might have seizures. The symptoms are scored using clinical tools, and babies with high scores often require medication and hospital monitoring. Early recognition of these symptoms is crucial so that babies can receive the care and comfort they need.

How is NAS diagnosed in a newborn?

Diagnosis of NAS is made through a combination of clinical observation and laboratory tests. Healthcare providers assess symptoms using tools like the Finnegan scoring system. Additionally, they may test the baby’s urine, meconium (first stool), or umbilical cord tissue for drugs. A detailed maternal history is also essential. In many cases, mothers may be afraid to disclose drug use due to stigma, so it’s important that healthcare providers approach this topic with sensitivity and support.

Is NAS treatable, and can babies recover completely?

Yes, NAS is treatable, and with the right support, many babies recover completely. Mild cases often improve with non-drug therapies like swaddling, quiet environments, and frequent feeding. More severe cases are treated with medications like morphine or methadone, which are gradually tapered off. The treatment plan is tailored to each baby’s symptoms. Long-term outcomes vary—some children may develop normally, while others may experience learning or behavioral difficulties, especially if postnatal care is lacking. Continued follow-up and early developmental support can make a big difference in long-term health.

What medications are used to treat NAS in infants?

The most commonly used medications are morphine and methadone, which help relieve withdrawal symptoms. The dosage is carefully calculated and gradually reduced over time. In some cases, phenobarbital or clonidine may be used, particularly if the baby was exposed to multiple drugs. These medications don’t cure the syndrome but help manage symptoms safely. Babies are monitored closely for side effects and improvement. The goal is to wean the infant off medication while ensuring comfort, growth, and stability.

How long do NAS symptoms last in newborns?

The duration of NAS symptoms can vary. For short-acting opioids like heroin, symptoms may peak within the first 3 days and resolve in about a week. For long-acting drugs like methadone or buprenorphine, symptoms may appear later and last several weeks. Most babies with moderate to severe NAS stay in the hospital for 2–4 weeks, sometimes longer if medication is needed. Babies exposed to multiple substances may experience more prolonged withdrawal. Follow-up care and ongoing monitoring are essential after discharge to ensure proper development.

Can mothers still breastfeed if they used opioids during pregnancy?

In most cases, breastfeeding is encouraged, even for mothers on methadone or buprenorphine maintenance therapy. These medications pass into breast milk in very small amounts and can actually help ease the baby’s withdrawal symptoms. However, breastfeeding is not recommended if the mother is using illicit drugs, has HIV, or has untreated psychiatric conditions that impair judgment. Each case must be assessed individually by healthcare providers. Breastfeeding also promotes bonding and emotional well-being for both mother and baby.

Does every baby born to a mother on opioids develop NAS?

Not necessarily. Although many babies exposed to opioids do develop some withdrawal symptoms, the severity and presence of NAS vary widely. Factors such as the type of drug, timing of the last dose, duration of use, and whether the mother is in a stable treatment program all influence outcomes. Some babies have mild or no symptoms and may not require medical treatment. Close monitoring in the first week of life is essential for early detection and management.

What can be done to prevent NAS during pregnancy?

The most effective way to prevent NAS is to avoid the use of addictive substances during pregnancy. For women with substance use disorders, entering a supervised treatment program with medications like methadone or buprenorphine can improve both maternal and neonatal outcomes. Preconception planning, early prenatal care, mental health support, and access to non-judgmental medical professionals are key. Education and public health initiatives aimed at reducing prescription drug misuse are also essential in the long-term strategy against NAS.

Is NAS a form of child abuse?

No. NAS is a medical condition, not a form of abuse. While maternal drug use can have harmful effects, it’s important to view NAS with empathy and understanding. Many mothers are battling addiction, mental health issues, or socio-economic challenges. Labelling NAS as abuse may discourage women from seeking help. A compassionate, evidence-based approach that supports both mother and baby is far more effective in promoting long-term well-being.

Research References on Neonatal Abstinence Syndrome