DESCRIPTION

• Neonatal opioid withdrawal syndrome (NOWS) occurs due to intrauterine exposure to maternal opioid medications (whether the mother is on maintenance opioid therapy or using illicit or prescribed opioids), causing a postnatal withdrawal syndrome.
• Signs of NOWS include gastrointestinal (GI) tract dysfunction, central nervous system (CNS) irritability, and autonomic overreactivity following birth secondary to a cessation of opioid exposure following birth.
• Iatrogenic drug withdrawal syndrome may be seen in infants and children treated with opioids (following severe illness or surgery with similar symptoms) but is not the focus of this chapter.

EPIDEMIOLOGY

• NOWS symptoms occur in 60–80% of neonates with intrauterine opioid exposure.
• In the United States, there was a marked 5-fold increase in NOWS cases from 2000 to 2012, and these numbers continue to rise.

ETIOLOGY

Intrauterine exposure to maternal licit or illicit opioid use with abrupt cessation of the exposure at clamping and cutting of the umbilical cord

RISK FACTORS

History of maternal chronic pain, medication-seeking behaviors, opioid maintenance therapy, illicit drug use, multidrug use (i.e., nicotine, cocaine, benzodiazepines, selective serotonin reuptake inhibitors [SSRIs]), homelessness, history of sexual abuse or domestic violence

GENERAL PREVENTION

• Prenatal education and counseling of at-risk women
• Prenatal treatment—opioid maintenance therapy
• Avoidance of abrupt drug cessation during pregnancy

PATHOPHYSIOLOGY

• Opioids are low molecular weight, lipophilic compounds that easily cross the placenta, increasingly as gestation progresses.
• Opioids easily cross fetal blood–brain barrier.
• Opioid receptors are extensive in CNS as well as the peripheral nervous system, GI tract, and other organ systems.
• Opioids have a prolonged half-life in the fetus.
• Neonatal neurobehavioral dysregulation is the major manifestation of NOWS.

COMMONLY ASSOCIATED CONDITIONS

• Placental abruption
• Poor intrauterine growth and/or small for gestational age
• Premature birth
• Birth defects (rare)
• Feeding problems
• Seizures (uncommon)