Neonatal abstinence syndrome, including neonatal opioid withdrawal syndrome (NOWS), is a clinical diagnosis that describes the constellation of symptoms that result from the abrupt discontinuation of chronic fetal exposure to most commonly opioid use in pregnancy. Neonatal abstinence syndrome describes newborns at risk for polysubstance exposure, including opioids whereas neonatal opioid withdrawal syndrome describes opioid-only withdrawal symptoms (55). We will use the term neonatal abstinence syndrome for both opioid-only and polysubstance exposure. In this article, the authors provide a brief historical background, as well as information on the pathophysiology, clinical spectrum, and management of neonatal abstinence syndrome. The clinical or consulting neurologist will find this information useful in formulating a differential diagnosis when faced with a newborn with signs and symptoms pertaining to central nervous system/autonomic dysfunction.
• The incidence of neonatal abstinence syndrome has increased steadily over the last decade. From 2000 to 2014 there was a nearly 7-fold increase in the number of newborns born with neonatal abstinence syndrome (62).
• Management of neonatal abstinence syndrome involves appropriately identifying infants at risk for withdrawal, along with assessment of symptoms with objective assessment tools and management of symptoms with supportive measures and with pharmacologic therapy where appropriate.
• Standardization of care, which includes standardization of scoring, use of nonpharmacologic and pharmacologic therapy, as well as strict adherence to treatment protocols, have all been shown to decrease the duration of pharmacologic therapy and length of hospital stay.
Historical note and terminology
Medical use of opium dates to Mesopotamian and Egyptian cultures. However, morphine, named after Morpheus, the Greek god of dreams, was only isolated from opium in 1806, followed by the isolation of codeine. Congenital morphinism was first described in Germany in 1875 in a newborn who had signs of opioid withdrawal at birth. The first report of successful treatment in an infant was in 1903 (47).
Opioids can be divided into natural, semisynthetic, and synthetic opioids. Opium, morphine, and codeine are examples of natural opiates. Semisynthetic opioids are derived from opium and examples include heroine, hydromorphone, oxycodone, and buprenorphine. Examples of synthetic substances with morphine-like activities include meperidine, fentanyl, methadone, and propoxyphene (23).
Other substances such as alcohol, tobacco, benzodiazepine, and selective serotonin-reuptake inhibitors (SSRIs) can provoke symptoms similar to those occurring in neonatal abstinence syndrome.