Neonatal abstinence syndrome (NAS) refers to a wide group of signs and symptoms in infants who are experiencing withdrawal from drugs they were exposed to in the uterus. Doctors most often associate NAS with maternal opioid use.

The number of infants born with NAS has increased in recent years. Between 2010 and 2017, the incidence of NAS increased by 82% in almost every state in the United States.

According to the Healthcare Cost and Utilization Project (HCUP), an infant with NAS is born every 24 minutes in the U.S., and doctors diagnose over 59 infants daily.

This article looks at what NAS is, along with its symptoms, diagnosis, treatments, and possible complications. It also looks at prevention and the long-term outlook for infants with NAS, and answers some frequently asked questions.

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An infant may be born with NAS when a pregnant person uses certain substances, such as opioids, and exposes the fetus to those substances in the uterus.

When the infant is born and is suddenly no longer exposed to those substances, they may experience withdrawal.

Doctors diagnose 60–80% of newborns who have had opioid exposure with symptoms of NAS.

NAS can affect multiple systems in the body and most often affects the gastrointestinal (GI) system, central nervous system (CNS), and autonomic nervous system.

Symptoms of NAS can vary substantially depending on the substance the infant is in withdrawal from, the overall accumulation of the substance, the time of the last exposure, whether multiple substances are involved, and other factors.

Initial symptoms of NAS can include:

  • diarrhea
  • tremors
  • excessive, high pitched crying
  • exaggerated Moro reflex, which is a response babies present when they feel startled or as if they are falling
  • stiffness from too much muscle tone
  • irritability
  • sneezing

Infants with NAS may present symptoms specific to the body systems the withdrawal affects:

GI symptoms can include:

CNS symptoms may include:

Autonomic symptoms may include:

Doctors may diagnose NAS based on a history of substance use by the person carrying the baby or based on the suspicion of substance use.

In some cases, a person may not wish to disclose substance use for fear of judgment or repercussions. In these cases, doctors may perform certain tests for toxicological confirmation.

Doctors may test the infant’s meconium (first bowel movement), urine, hair, or cord blood for toxins. Doctors may then observe the infant for 3–7 days before discharge.

Treatments for infants with NAS may involve:

  • medication to treat withdrawal, such as buprenorphine, morphine, and methadone, in tapering doses
  • a diet of high calorie baby formula to help with growth
  • intravenous fluids to prevent dehydration

Treatment may also include non-pharmacological measures, such as:

  • keeping the baby’s environment quiet and dark to help calm them
  • using calming techniques, such as gentle vertical rocking and swaddling
  • providing skin-to-skin contact
  • applying a topical barrier cream to reduce the baby’s irritability from diaper rash due to diarrhea
  • using a pacifier
  • ensuring regular, on-demand feeding
  • breastfeeding or chestfeeding, as opioids are typically only present in minute quantities in breast milk

There are a variety of potential complications that doctors associate with NAS.

NAS may affect infants in the short term but may also have long-term effects. More research is necessary to understand the possible long-term outcomes for babies with NAS.

Possible complications of NAS include:

A pregnant person should disclose their pregnancy to a doctor who is prescribing them medication to ensure it is safe for the fetus, as some prescription drugs can cause NAS.

If a person is pregnant and uses substances that may cause NAS — such as opioids, benzodiazepines, antidepressants, barbiturates, codeine, heroin, or others — they should speak with a healthcare professional to discuss treatment.

A person should not suddenly stop using the substance, as this may cause severe health problems for the fetus and may result in the fetus’s death.

If a pregnant person is using opioids, they should discuss medication-assisted treatment (MAT) with a healthcare professional.

Doctors may be able to treat infants with NAS more easily and effectively when they are born from a person who has undergone MAT.

Most infants with NAS will recover in 5–30 days with treatment.

However, there are potential long-term side effects of NAS. While more research is necessary to better understand these potential outcomes, people who had NAS as infants may be at higher risk of:

  • difficulties with language and speech
  • developmental delays
  • vision problems
  • problems with sleep
  • learning and behavior problems
  • motor problems
  • ear infections

Below are answers to some frequently asked questions about neonatal abstinence syndrome.

How long does neonatal abstinence syndrome last?

The time it takes an infant to recover from NAS can vary, depending on factors such as which substance or substances they are withdrawing from.

Most infants will recover from NAS within 5–30 days. However, there may be potential long-term complications.

Does taking antidepressants during pregnancy cause neonatal abstinence syndrome?

Researchers have connected the use of selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs) during pregnancy to certain withdrawal signs and symptoms in babies.

According to the U.K. mental health charity Mind, using antidepressants during late pregnancy may pose a risk of the newborn experiencing withdrawal symptoms.

Withdrawal symptoms for SSRIs and SNRIs may include:

Withdrawal symptoms for tricyclics may include:

However, a person should contact a doctor to discuss the use of antidepressants during pregnancy. It may be safer for the pregnant person’s mental health to continue using their medication.

People should not stop taking antidepressants abruptly.

NAS can occur in infants who are exposed to certain substances, such as opioids, while they are in the uterus.

Infants may become dependent on these substances and may experience withdrawal after birth, when their exposure to the substances suddenly ends.

Infants with NAS may present with a variety of symptoms, such as vomiting, diarrhea, sneezing, tremors, and high pitched crying.

Babies with NAS may be at higher risk of complications such as jaundice, low birth weight, SIDS, and seizures.

Doctors may treat infants with NAS using a combination of non-pharmacological soothing techniques and medications. Most infants will recover within 1 month with treatment.

There may be long-term effects for people born with NAS, but more research is necessary to fully understand the effects over a long period.