Meconium analysis for cocaine: a validation study and comparison with paired urine analysis

Area of Science:

• Neonatal toxicology
• Analytical chemistry
• Forensic toxicology

Background:

• Neonatal drug exposure is a significant public health concern.
• Accurate detection of illicit substance use during pregnancy is crucial for infant health.
• Meconium analysis offers a longer detection window compared to urine testing.

Purpose of the Study:

• To establish the validity of a drug-screening method for cocaine and benzoylecgonine in meconium.
• To compare the sensitivity of meconium and urine drug testing in neonates.
• To assess the accuracy of fluorescence polarization immunoassay (FPIA) with gas chromatography-mass spectrometry (GC-MS) confirmation for meconium drug screening.

Main Methods:

• Analysis of 82 consecutive newborn meconium specimens using FPIA, Kinetic Interaction of Microparticles in Solution (KIMS), and GC-MS.
• Concurrent analysis of 54 paired urine and meconium specimens from neonates.
• Urine drug testing by immunoassay (enzyme multiplied immunoassay [EMIT] technique).
• Meconium testing by FPIA with GC-MS confirmation.

Main Results:

• Meconium drug testing identified 25.9% positive cases, significantly higher than urine testing (9.3%, p = .011).
• FPIA followed by GC-MS confirmation demonstrated high accuracy in detecting cocaine or benzoylecgonine in meconium.
• Ten true positives for cocaine or benzoylecgonine were confirmed by GC-MS in meconium specimens.

Conclusions:

• Screening meconium specimens by FPIA with GC-MS confirmation is a highly accurate method for detecting cocaine and its metabolites.
• Meconium drug testing is more sensitive than urine testing for identifying neonatal cocaine exposure.
• This method aids in the accurate assessment of prenatal drug exposure in newborns.