Lawyers seeking to create a $1 billion medical monitoring trust for babies born addicted to opioids lost their bid to create a separate multidistrict litigation proceeding.

The U.S. Judicial Panel on Multidistrict Litigation in an order Thursday refused to transfer class actions brought on behalf of 40 percent of the nation’s opioid-addicted babies, the latest group of plaintiffs suing manufacturers and distributors over a nationwide epidemic tied to the prescription painkillers. The panel concluded that there would be “substantial overlap” with the multidistrict litigation it created a year ago for opioid lawsuits.