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Test Code THCM 11-nor-Delta-9-Tetrahydrocannabinol-9-Carboxylic Acid (Carboxy-THC) Confirmation, Meconium

Reporting Name

Carboxy-THC Confirmation, M

Useful For

Detecting in utero drug exposure to marijuana (tetrahydrocannabinol) up to 5 months before birth

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Meconium


Ordering 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
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

G0480

80349 (if appropriate for select payers)

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 days

Method 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.