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HelpTest Code THCM 11-nor-Delta-9-Tetrahydrocannabinol-9-Carboxylic Acid (Carboxy-THC) Confirmation, Meconium
Reporting Name
Carboxy-THC Confirmation, MUseful For
Detecting in utero drug exposure to marijuana (tetrahydrocannabinol) up to 5 months before birth
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
MeconiumOrdering Guidance
For chain-of-custody testing, order THCMX / 11-nor-Delta-9-Tetrahydrocannabinol-9-Carboxylic Acid (Carboxy-THC) Confirmation, Chain of Custody, Meconium.
Specimen Required
Supplies: Stool container, Small (Random), 4 oz (T288)
Container/Tube: Stool container
Specimen Volume: 1 g (approximately 1 teaspoon)
Collection Instructions: Collect entire random meconium specimen.
Specimen Minimum Volume
0.3 g (approximately 1/4 teaspoon)
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Meconium | Frozen (preferred) | 28 days | |
| Refrigerated | 21 days | ||
| Ambient | 14 days |
Reference Values
Negative
Positives are reported with a quantitative liquid chromatography tandem mass spectrometry result.
Cutoff concentration: 5 ng/g
Day(s) Performed
Monday through Sunday
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
80349
G0480 (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| THCM | Carboxy-THC Confirmation, M | 69007-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 31863 | Carboxy-THC | 69007-3 |
| 31876 | Interpretation | 69050-3 |
| 31877 | Chain of Custody | 77202-0 |
Interpretation
The presence of 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid at 5 ng/g or greater is indicative of in utero drug exposure up to 5 months before birth.
Clinical Reference
1. Huestis MA: Marijuana. In: Levine B ed. Principles of Forensic Toxicology. 2nd ed. AACC Press; 2003:229-264
2. O'Brein CP: Drug addiction and drug abuse. In: Burton LL, Lazo JS, Parker KL, eds. Goodman and Gilman's The Pharmacological Basis of Therapeutics. 11th ed. McGraw-Hill; 2006
3. Baselt RC: Tetrahydrocannabinol. In: Baselt RC, ed. Disposition of Toxic Drugs and Chemical in Man. 8th ed. Biomedical Publications; 2008:1513-1518
4. Ostrea EM Jr, Knapop DK, Tannenbaum L, et al: Estimates of illicit drug use during pregnancy by maternal interview, hair analysis, and meconium analysis. J Pediatr. 2001;138:344-348
5. Ostrea EM Jr, Brady MJ, Parks PM, Asensio DC, Naluz A: Drug screening of meconium in infants of drug-dependent mothers: an alternative to urine testing. J Pediatr. 1989;115:474-477
6. Ahanya SN, Lakshmanan J, Morgan BL, Ross MG: Meconium passage in utero: mechanisms, consequences, and management. Obstet Gynecol Surv. 2005 Jan;60(1):45-56
7. Langman LJ, Bechtel LK, Meier BM, Holstege C. Clinical toxicology. In: Rifai N, Horvath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier;2018:883-884
Report Available
2 to 3 daysMethod Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.