Strahan AE, et al. - Since little is understood about the impact of prenatal opioid exposure on physical and developmental health, researchers sought to provide new national incidence and cost estimates for neonatal abstinence syndrome (NAS), a withdrawal syndrome primarily occurring in infants with in utero exposure to opioids, in 2016. The NAS is a key indicator of the immediate impact of the opioid crisis. From 2004 to 2014, NAS incidence rates rose from 1.5 to 8.0 per 1,000 hospital births in the USA. Total hospital costs in 2012 touched $316 million and accounted for 4% of all neonatal intensive care unit hospital days nationwide in 2013.