BACKGROUND: Although in utero opioid exposure is the primary cause of neonatal abstinence syndrome (NAS), other non-opioid substances have been linked to NAS diagnoses. NAS is a constellation of central nervous system, metabolic vasomotor, respiratory, and gastrointestinal disturbances a newborn experiences resulting from withdrawal. The risk of NAS and NAS requiring pharmacological treatment among non-opioid exposed infants is unknown. This research is important because standardized hospital protocols to diagnose, pharmacologically treat, and discharge NAS diagnosed infants, regardless of drug exposure, are based on antenatal opioid exposure.
METHODS: A retrospective medical chart review was analyzed for 476 substance exposed mother-infant dyads with births occurring between January 1st 2009 and March 3rd 2014. There was a total of 137 NAS diagnosed infants (ICD-9-CM 779.5), 75 of which required pharmacological treatment. Risk of NAS, risk of NAS requiring treatment, and odds of NAS via logistic regression were observed among drug class-specific exposure groups. Exposure status was classified via neonatal meconium and umbilical cord tissue drug screening.
RESULTS: The absolute risk of NAS was 29% and of those diagnosed 54% required pharmacological treatment. There was variation in risk of NAS between drug classes. Single-substance and poly-substance opioid exposure had the highest risk of NAS while sedative-only exposure had the highest risk of NAS requiring treatment. After controlling for potential biopsychosocial confounders, the odds of a NAS diagnosis among opioid exposed neonates was three times the odds of a NAS diagnosis among neonates without a positive drug screen [single-substance: OR=3.72, 95% CI: 1.54, 9.98, poly-substance: OR=3.52, 95% CI: 1.13, 10.98]. In addition, the number of prenatal care visits [OR = 0.92; 95% CI: 0.86, 0.99] and maternal opioid maintenance therapy enrollment [OR = 6.54; 95% CI: 2.30, 18.57] were independent risk factors for a NAS diagnosis.
CONCLUSIONS: A NAS diagnosis most commonly occurred with in utero opioid single or poly-substance exposure, though risk among non-opioid exposed neonates ranged from 11% to 33%. There are no drug-specific diagnostic criteria or treatment protocols for NAS. Future examination of non-opioid based NAS protocols and studies regarding NAS severity with sedative in utero exposures are warranted.