Source

Patrick SW, Davis MM, Lehmann CU, Cooper WO. Increasing incidence and geographic distribution of neonatal abstinence syndrome: United States 2009 to 2012 [published correction appears in J Perinatol. 2015 Aug;35(8):667. Lehman, C U [corrected to Lehmann, C U]]. J Perinatol. 2015;35(8):650–655. doi:10.1038/jp.2015.36

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4520760/