The incidence of babies born in the United States with neonatal abstinence syndrome (NAS) quadrupled from 1999 to 2013, from 1.5 to 6.0 cases per 1,000 hospital births, according to the Centers for Disease Control and Prevention (CDC).

NAS is a group of problems that occur in a newborn who was exposed to addictive opiate drugs while in the mother’s womb. Babies with NAS experience opioid withdrawal symptoms such as tremors, increased muscle tone, high-pitched crying and seizures, the CDC researchers reported.

Maine, Vermont and West Virginia had the highest rates of NAS among the 28 states involved in the study, HealthDay reports.