Detection of In Utero Marijuana Exposure by GCMS, Ultra-Sensitive ELISA and LCTOFMS Using Umbilical Cord Tissue

Smoking marijuana during pregnancy can cause health problems in the neonate. The detection of exposure can guide treatment to meet the short- and long-term medical and social needs. Umbilical cord tissue was analyzed for 11-nor-delta-9-carboxy-tetrahydrocannabinol (THC-COOH) by gas chromatographymass spectrometry (GCMS), and compared with ultra-sensitive enzyme-linked immunosorbent assay (ELISA) and liquid chromatography time-of-flight mass spectrometry (LCTOFMS). Fortified extracts of drug-free cord tissue were used to determine the sensitivity and specificity of the LCTOFMS and ELISA assays, and 16 de-identified patient specimens previously analyzed by GCMS were tested for THC-COOH by both methods. The cutoffs were 0.050 ng/g for the GCMS assay, 0.1 ng/g for the ELISA assay and 1 ng/g for the LCTOFMS assay. Twelve specimens were negative by all three methods. Seven specimens were positive by GCMS with concentrations from 0.066 to 6.095 ng/g. ELISA and LCTOFMS did not detect one specimen that was positive by GCMS. LCTOFMS missed one specimen that was detected by GCMS and ELISA. Five positive specimens were detected by all three methods. These results were consistent with the cutoff for each method. No false positives were detected by LCTOFMS or ELISA. Umbilical cord tissue is a viable specimen for the detection of in utero marijuana exposure. ELISA and GCMS were more sensitive than LCTOFMS for the detection of THC-COOH in cord tissue, with the GCMS method providing superior sensitivity.