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What is neonatal abstinence syndrome?

Neonatal abstinence syndrome (NAS) is a term for a group of problems a baby experiences when withdrawing from exposure to narcotics. It's estimated that 3 to 50 percent of newborn babies have been exposed to maternal drug use, depending on the population and area of the country.

Why is neonatal abstinence syndrome a concern?

When a mother uses illicit substances, she places her baby at risk for many problems. A mother using drugs may be less likely to seek prenatal care, which can increase the risks for her and her baby. In addition, women who use drugs are more likely to use more than one drug, which can complicate the treatment. The risk of contracting HIV and AIDS is also greater among intravenous (IV) drug users.

In addition to the specific difficulties of withdrawal after birth, problems in your baby may include:

Specific drugs often times cause specific problems in your baby:

  • Heroin and other opiates, including methadone, can cause significant withdrawal in your baby, with some symptoms lasting as long as four to six months. Seizures may also occur and are more likely in babies born to methadone users.
  • Prenatal use of amphetamines is associated with low birthweight and premature birth, and may cause intracranial (in the head) bleeding in your baby.
  • A mother's prenatal cocaine use may be related to an increased risk of sudden infant death syndrome (SIDS).
  • Marijuana use is linked to lower birthweight and size of your baby.
  • Alcohol use in pregnancy also has significant effects on the fetus and your baby. The baby's growth during pregnancy and after birth is slowed, and she may have deformities of the head and face, heart defects, and mental retardation. Withdrawal symptoms from alcohol may last up to 18 months.
  • Cigarette smoking has long been known for its effects on the fetus. Generally, smokers have smaller babies than non-smokers. Babies of smokers may also be at increased risk for premature birth and stillbirth.

Symptoms & Causes

What are the symptoms of NAS?

Symptoms of NAS may vary depending on the type of substance used, the last time it was used, and whether your baby is full-term or premature. Symptoms of withdrawal may begin as early as 24 to 48 hours after birth, or as late as five to 10 days. Alcohol withdrawal may begin within a few hours after birth.

Symptoms of withdrawal in full-term babies may include:

  • Tremors (trembling)
  • Irritability (excessive crying)
  • Sleep problems
  • High-pitched crying
  • Tight muscle tone
  • Hyperactive reflexes
  • Seizures
  • Yawning, stuffy nose, and sneezing
  • Poor feeding and suck
  • Vomiting
  • Diarrhea
  • Dehydration
  • Sweating
  • Fever or unstable temperature
  • Rapid breathing

An accurate report of the mother's drug usage is important in order for doctors to properly treat the baby. A neonatal abstinence scoring system may be used to help diagnose and grade the severity of the withdrawal. Using the scoring system, points are assigned for certain signs and symptoms and the severity of each. This scoring may also help in planning treatment.

What causes neonatal abstinence syndrome?

Almost every drug passes from the mother's blood stream through the placenta to the fetus. Illicit substances that cause drug dependence and addiction in the mother also cause the fetus to become addicted. At birth, your baby's dependence on the substance continues. However, since the drug is no longer available, your baby's central nervous system becomes overstimulated causing the symptoms of withdrawal.

Some drugs are more likely to cause NAS than others, but nearly all have some effect on your baby. Opiates, such as heroin and methadone, cause withdrawal in about half of babies exposed prenatally.

  • Cocaine may cause some withdrawal, but the main symptoms in your baby are due to the toxic effects of the drug itself.
  • Other drugs, such as amphetamines, barbiturates, and narcotics, can also cause withdrawal.
  • Alcohol use causes withdrawal in your baby, as well as a group of problems including fetal alcohol syndrome.

Diagnosis & Treatments

How is neonatal abstinence syndrome treated?

Babies suffering from withdrawal are irritable and often have a difficult time being comforted.

  • Swaddling, or snugly wrapping your baby in a blanket, may help comfort your baby.
  • Babies also may need extra calories because of their increased activity and may need a higher calorie formula. Intravenous (IV) fluids are sometimes needed if your baby becomes dehydrated or has severe vomiting or diarrhea.

Some babies may need medications to treat severe withdrawal symptoms, especially for seizures. Specific drugs for treating withdrawal are:

  • Methadone for heroin and other opiate withdrawal
  • Benzodiazepines (for alcohol withdrawal)

Other drugs are also being used to help relieve the discomfort and problems of withdrawal. The treatment drug is usually in the same class as the substance your baby is withdrawing from. Once the signs of withdrawal are controlled, the dosage is gradually decreased to help wean your baby off the drug.

How we care for NAS

Boston Children's is devoted to addressing the needs of high-risk babies and their families. One such program is our Young Parents Program (YPP), which provides quality medical care and health education to teen or at-risk parents and their children in low-income and at-risk environments.

YPP is part of the Children's Hospital Primary Care Center (CHPCC), which is dedicated to helping young parents learn positive parenting skills, attitudes, and behaviors so their child experiences healthy development and growth in the critical first years.

Practitioners Who Specialize In This Condition (3)

Philip Levy

Philip Levy, MD

Physician in Medicine, Division of Newborn Medicine
Associate Professor of Pediatrics, Harvard Medical School
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Newborn Medicine

The Division of Newborn Medicine specializes in treating babies with a wide range of congenital and acquired conditions.

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