Neonatal withdrawal or neonatal abstinence syndrome (NAS) or neonatal opioid withdrawal syndrome (NOWS) is a withdrawal syndrome of infants after birth caused by in utero exposure to drugs of dependence, most commonly opioids. Common signs and symptoms include tremors, irritability, vomiting, diarrhea, and fever. NAS is primarily diagnosed with a detailed medication history and scoring systems. First-line treatment should begin with non-medication interventions to support neonate growth, though medication interventions may be used in certain situations.In 2017, approximately 7.3 per 1,000 hospitalized infants in the United States were diagnosed with NOWS. Not all opioid-exposed infants will show clinical signs of withdrawal after birth. Clinical signs range from mild to severe, depending on the quantity and type of substance exposure.The most common form on neonatal withdrawal occurs after in utero exposure, however, iatrogenic withdrawal can also occur after medications are used to treat critically ill infants after they are born. Signs and symptoms
Drug and alcohol use during pregnancy can lead to many health problems in the fetus and infants, including neonatal abstinence syndrome (NAS). The onset of clinical presentation typically appears within 48 to 72 hours of birth but may take up to 8 days. The signs and symptoms of NAS may be different depending on which substance the mother used.Common signs and symptoms in infants with NAS may include:
Signs due to hyperactivity of the central nervous system:
Tremors (trembling)
Irritability (excessive mood crying)
Sleep problems
High-pitched crying
Muscle tightness
Hyperactive reflexes
Seizures (2% to 11%), notably this clinical sign is controversial given it does not occur in other populations experiencing opioid withdrawal.
The medical history should include physical and mental health problems, prescription and non-prescription medication use, nutritional supplement use, history of alcohol and substance use, childhood adversities, cultural and social beliefs, past traumatic experiences, and infectious diseases such as HIV. Since the medical history of the birth giver may not be available immediately after delivery, some testing needs to be done in the infant to confirm possible exposure. Infants urine, meconium, umbilical cord tissue or hair can be used for testing. The timing of urine sample collection is critical because some drugs may become undetectable after they are metabolized and eliminated from the body. Also, urine test results can only confirm if the fetus was exposed to drugs a few days before birth. Meconium testing can be used to confirm drug exposure in earlier stage of pregnancy, but the collecting process is more difficult. Umbilical cord tissue testing is a relatively new testing method and its accuracy is still controversial. The mothers blood and urine sample should also be collected for drug screening. Chest X-rays can confirm or infirm the presence of heart defects. Assessment
Depending on what hospital setting the infant is in, different scoring systems are used for assessing the severity and the need for medication treatment in neonatal withdrawal syndrome. One challenge with existing clinical predication tools is that they were designed to assess opiate withdrawal only. The Finnegan Neonatal Abstinence Scoring System (FNASS), or its modified version is the most widely used prediction tool currently in the United States.