The number of pregnant women with opioid use disorder at labor and delivery has more than quadrupled since 1999, according to new analysis from the Centers for Disease Control and Prevention. The report finds significant increases in the 28 states with data available.

The highest rates existed in Vermont (48.6 cases per 1,000 deliveries) and West Virginia (32.1), according to the report. Washington, D.C. (0.7) and Nebraska (1.2) had the lowest rates. Georgia's rate was 2.07 per 1,000 deliveries.

Opioid use disorder is described as a pattern of opioid use that can result in health problems, disability or failure to meet responsibilities at work, school or home. OUD has been associated with a range of negative outcomes for both the mothers and their babies, including death, preterm birth, stillbirth and neonatal abstinence syndrome.

The most recent government data available on the incidence of neonatal abstinence syndrome, from 2012, shows an estimated 21,732 babies were born with the condition, a five-fold increase from a dozen years earlier.