An alarming rise in substance abuse has led many hospitals to initiate drug toxicology programs for pregnant women and newborns, writes Laura Newman in the March issue of CLN
However, in the absence of a universal evidence-based protocol on referrals and drug screening among this population, states and hospitals have been left to their own devices as to what types of screening tests they should use and whether they should initiate targeted testing—or screen all newborns and mothers.
Newman’s article highlights the work Scott Wexelblatt, MD, a neonatologist at Cincinnati Children’s Perinatal Institute, has conducted on this issue, after seeing heroin and painkiller use spike in the Cincinnati area. A study Wexelblatt conducted several years ago determined that more than 5% of mothers tested positive for drugs upon admission to the hospital—with 3.2% testing positive for opioids.
“Opioids are what we worry about most,” he told CLN. Withdrawal symptoms are reported in up to 94% of newborns exposed to this class of drugs and many require pharmacologic treatment.
Some experts have made the case for universal screening, claiming that low-income women are often unfairly targeted under risk-based screening protocols. The downside to universal screening, however, is it “is extremely expensive and diagnostic yield is poor,” Gwen McMillin, PhD
, director of the toxicology laboratory and pharmacogenetics at ARUP Laboratories in Salt Lake City, told CLN.
A number of specimen collection methods are available, yet each has its own strengths and weaknesses. Hospitals tend to favor maternal urine testing because of its rapid turnaround time. However, this method is prone to false positives in both maternal and newborn samples.
Some laboratories have favored meconium samples as a way to screen newborns because its window of detection extends back into the pregnancy.
One thing labs are in agreement about is the use of mass spectrometry to verify positive test results. In Cincinnati, for example, Wexelblatt says the protocol for hospitals is to use mass spectrometry to confirm the initial results of urine immunoassays.
Pick up the March issue of CLN
and learn more about the legal implications of reporting false positives in newborn and maternal drug screening, and why confirmatory testing is so essential—not only for labs, but also for patients.