Evaluating a switch from meconium to umbilical cord tissue for newborn drug testing: A retrospective study at an academic medical center.

BACKGROUND: The objective of this study was to compare detection rates of newborn drug exposure at an academic medical center transitioning from meconium to umbilical cord tissue toxicology testing.

METHODS: We performed an Institutional Review Board-approved retrospective chart review on all newborns (n=2072) for whom newborn drug testing was ordered at our academic medical center between June 2012 and August 2015 (in August 2013, umbilical cord tissue became the preferred specimen).

RESULTS: Meconium toxicology testing was positive for at least one compound in 221 cases (21.3% of 1037 total specimens), with non-medical drug use identified in 85 cases (8.2%). Umbilical cord tissue toxicology testing was positive for at least one compound in 302 cases (29.2%), with non-medical drug use identified in 107 cases (10.3%). Of the cases involving non-medical drug use, the most common compounds detected were tetrahydrocannabinol and amphetamines. Non-medical drug use did not differ significantly between meconium and umbilical cord tissue, either as a total or for classes of drugs such as amphetamines, cannabinoids, and opiates. Maternal non-medical use of tramadol (not tested for in meconium) was identified in 5 cases (0.4%). There were significant differences in rate of detection of iatrogenic medications. Specifically, morphine, lorazepam, phenobarbital, and codeine were more commonly detected in meconium, while oxycodone was more commonly detected in umbilical cord tissue.

CONCLUSIONS: Umbilical cord tissue toxicology testing yielded a similar detection rate compared to meconium testing. The use of umbilical cord tissue avoids detection of medications given to the neonate prior to meconium collection.