A lab in Utah is analyzing sections of umbilical cords to look for evidence of mothers’ drug use, Medical Daily reports. Quickly identifying which infants have been exposed to drugs, and which drugs they were exposed to, can provide valuable information to neonatal specialists treating the babies, the lab says.

ARUP Laboratories, which is affiliated with the University of Utah, was the second lab in the nation to offer umbilical cord testing, the article notes. Before umbilical cord testing was developed, doctors would analyze babies’ exposure to drugs through their meconium (first stool). Testing the umbilical cord is faster, according to the article. Umbilical cord testing can take up to 72 hours.

“Sometimes babies are already in the throes of withdrawal symptoms but physicians can’t determine what drugs they are dealing with until test results are available,” Dr. Gwen McMillin, Medical Director of ARUP’s Clinical Toxicology Laboratories, said in a press release.

The number of babies treated for the drug-withdrawal syndrome known as neonatal abstinence syndrome (NAS) has almost quadrupled in the last decade, according to a recent study.

Babies born with NAS undergo withdrawal from the addictive drugs their mothers took during pregnancy, such as oxycodone, morphine or hydrocodone. NAS affected seven babies for every 1,000 admitted to a neonatal intensive care unit (NICU) in 2004. That number jumped to 27 infants per 1,000 by 2013.

The percentage of days spent in a NICU because of drug withdrawal rose from 0.6 percent to 4 percent during that time, the researchers reported in The New England Journal of Medicine. Eight centers reported that more than 20 percent of NICU days were spent caring for babies with the syndrome in 2013.