The Incidence of Neonatal Abstinence Syndrome Remained Stable in Eastern Denmark From 2013 to 2018 and Was Sometimes Associated With Cannabis

Aim: The incidence of neonatal abstinence syndrome (NAS) has risen, but published data are limited. The aim of this study was to investigate the incidence of NAS and the associated prenatal drug exposure in a Danish population. Methods: We conducted a historical multicentre cohort study of neonates treated for NAS during 2013–2018. The Danish National Patient Register identified 447 neonates with one of four predefined diagnoses. Reviews of the medical records showed that 98 of the neonates were pharmacologically treated for NAS. Results: The incidence of NAS in the 6-year period was stable at 0.6 per 1000 live births. The majority of neonates treated for NAS were born to mothers treated with analgesic opioids. However, one-third of the neonates treated for NAS were not exposed to opioids. The most frequent other drugs causing NAS were cannabis, benzodiazepines, antidepressants and psychoactive drugs. Half of the neonates were only exposed to a single drug; 14% were exposed to cannabis and 9% of all neonates treated for NAS were exposed to cannabis as a single drug in addition to tobacco. Conclusion: The incidence of NAS in the 6-year period was stable. Healthcare professionals should be aware of NAS after prenatal exposure to cannabis.