Incidence of Neonatal Abstinence Syndrome (NAS) in Castilla y Leon (Spain)

Introduction: Neonatal Abstinence Syndrome (NAS) is considered a Public Health problem that is defined as a group of symptoms that appear in the newborn due to withdrawal from intrauterine drug exposure. Objective: The aim of this study was to analyze the incidence of NAS in Castilla y Leon from 2000 to 2019. Methodology: Data of NAS cases in Castilla y Leon from 2000 to 2019 were obtained. NAS incidence per 1000 births was calculated and the correlation among data from different provinces and years was analyzed. Results: The cumulative incidence of NAS in Castilla y Leon per 1000 births between 2000-2019 was 0.91 parts per thousand, with great interprovincial variability. The provinces of Zamora and Palencia stand out, with high incidence rates of NAS despite their low birth rates. The temporal trend points towards a decrease in incidence from 2000 to 2019. Opioids such as methadone, cannabis, benzodiazepines and poly-drug use are the most prevalent drugs causing NAS, and it has also been observed that methadone is being replaced by cannabis as the major cause of NAS cases at the University Hospital in Salamanca in recent years. Conclusions: The incidence of NAS in Castilla y Leon decreased in 2004 and remained constant until 2019, but it shows great interprovincial variability. It is necessary to implement a national NAS Registry to obtain comprehensive information regarding its incidence.