Can Umbilical Cord and Meconium Results Be Directly Compared? Analytical Approach Matters

Area of Science:

• Toxicology
• Neonatal Health
• Analytical Chemistry

Background:

• Maternal drug use during pregnancy poses risks to newborns, including prematurity, birth defects, and developmental delays.
• Neonatal specimen testing, primarily using umbilical cord tissue (UC) and meconium, assesses fetal drug exposure.
• Limited comparative studies exist on drug positivity rates and concentrations between UC and meconium.

Purpose of the Study:

• To compare drug positivity rates and concentrations in paired umbilical cord tissue (UC) and meconium specimens.
• To evaluate the analytical sensitivity of UC versus meconium for detecting various drug classes in newborns.
• To identify common multidrug combinations in neonatal drug exposure assessments.

Main Methods:

• Retrospective analysis of 3,960 paired UC and meconium specimens from 13 US states.
• Testing for 32 drug analytes across 6 drug classes using liquid chromatography-tandem mass spectrometry (LC-MS-MS) and immunoassay screening.
• Separate analysis for 11-Nor-9-carboxy-tetrahydrocannabinol (THC-COOH) in 2,112 paired specimens.

Main Results:

• Individual analyte positivity rates were higher in UC, except for THC-COOH and cocaine.
• Drug concentrations were generally higher in meconium compared to UC, with phencyclidine as an exception.
• THC-COOH and opioids were the most frequent multidrug combination detected in both specimen types.

Conclusions:

• Umbilical cord tissue (UC) demonstrates greater analytical sensitivity for detecting neonatal drug exposure with current methodologies.
• Meconium exhibits higher drug concentrations for most compounds, indicating potential for developing more sensitive meconium-based assays.
• Comparative analysis aids in optimizing strategies for neonatal drug exposure testing.