Drug Detection Panel Testing, Meconium and Umbilical Cord Tissue

Last Literature Review: May 2022 Last Update:
  • Use to detect and document fetal drug exposure during the last trimester of a full-term pregnancy
  • Qualitative detection of drugs and drug metabolites
  • Confirmation testing usually not required due to analytical specificity (mass spectrometry)

Testing biological specimens such as meconium and umbilical cord tissue to detect prenatal drug exposure is preferred to maternal self-reporting because drug use is generally underreported by pregnant individuals.  For example, in a recent study, 2.6% of expectant individuals reported cannabis use to their healthcare providers; however, tetrahydrocannabinol (THC) metabolite was detected in 22.4% using an umbilical cord assay. 

Testing may be indicated for neonates born with unexplained neurological complications, growth restriction, or evidence of drug withdrawal symptoms (eg, neonatal abstinence syndrome [NAS]). Testing may also be indicated if the pregnant individual has a history of high-risk behaviors (eg, drug use/misuse/abuse), has had little or no prenatal care, or has experienced unexplained placental abruption or premature labor. 

Umbilical cord tissue testing may be preferable to meconium testing in certain contexts due to the ease and speed of collection and comparable window of detection.  Collecting both specimen types may increase detection of drug exposure. For a detailed discussion of newborn drug testing and the use of these specimens, refer to the Newborn Drug Screening - Meconium and Umbilical Cord Tissue topic.

Disease Overview

Timely detection of in utero drug exposure supports the identification and clinical management of affected neonates. ,  The actual time window for detecting exposure is drug dependent, but results are thought to represent approximately the last trimester of a full-term pregnancy. 

Detection of drugs is subject to the following factors :

  • Extent of maternal drug use
  • Specific drug(s) used
  • Deposition of drug analytes in meconium or umbilical cord tissue, which varies based on the chemistry of the drug analyte and the unique characteristics of each specimen
  • Quality of the specimen submitted for testing
  • Performance characteristics of test method

Test Interpretation

Analytic Sensitivity/Specificity

  • Sensitivity:
    • Detection of most compounds and metabolites is consistent between meconium and umbilical cord tissue testing, but results may not correlate with those of maternal urine testing or maternal self-report. In general, concentrations of drug analytes are lower in umbilical cord tissue than in meconium.
    • Dependent on method details and cutoff concentration for the analyte(s) of interest; cutoff concentrations have been selected to maximize agreement between meconium and umbilical cord tissue while assuring accuracy and precision requirements.
  • Specificity: high; mass spectrometric methodology and inclusion of multiple drug analytes/metabolites minimizes false positives and the need for secondary testing.

Drug Class/
Drug/Drug Metabolite

Cutoff Concentrations (ng/g)

Drug Detection Panels,
Meconium

Drug Detection Panels,
Umbilical Cord Tissuea

Barbiturates

Butalbital5025
Phenobarbital20075

Benzodiazepines

Alprazolam50.5
    Alpha-hydroxyalprazolamb50.5
Clonazepam51
    7-Aminoclonazepamb51
Diazepam51
Lorazepam205
Midazolam201
    Alpha-hydroxymidazolamb202
Nordiazepam201
Oxazepam202
Temazepam201
Zolpidem100.5

Cannabis

THC metabolitec,d50.2

Hallucinogens

Phencyclidine101

Kratom

Mitragynine25

Opioids and Gabapentin

Buprenorphine201
    Norbuprenorphineb200.5
Codeine200.5
Dihydrocodeine201
Fentanyl100.5
Gabapentin2010
Heroine
    6-Acetylmorphineb201
Hydrocodone200.5
    Norhydrocodoneb201
Meperidine202
Methadone102
    EDDPb101
Morphine200.5
    Hydromorphoneb200.5
Naloxone201
Oxycodone200.5
    Noroxycodoneb201
Oxymorphone200.5
    Noroxymorphoneb0.5
Propoxyphene1
Tapentadol202
Tramadol202
    N-desmethyltramadolb202
    O-desmethyltramadolb202

Stimulants

Amphetamine205
Cocaine200.5
    Benzoylecgonineb200.5
    Cocaethyleneb201
    M-hydroxy benzoylecgonineb201
Methamphetamine205
Methylenedioxymethamphetamine205
Methylphenidate20
Phentermine208

aUmbilical cord tissue testing for kratom alkaloids and ethanol metabolites is available separately. Associated cutoff concentrations can be found on the Laboratory Test Directory. Refer to Related Tests.

bDrug metabolite.

cFor multidrug testing that excludes THC metabolite, refer to Drug Detection Panel, Meconium, Qualitative (3004583) or Drug Detection Panel, Umbilical Cord Tissue, Qualitative (2006621)

dNote that delta-8 and delta-9 forms of THC metabolite cannot be distinguished in this test.

e6-Acetylmorphine is not always detected due to the short half-life of this analyte. Typically, heroin use is associated with the presence of morphine and codeine, as well as hydrocodone and hydromorphone.

Results

ResultsClinical SignificanceNotes
PresentOne or more drug analytes were detected

Consistent with fetal exposure to relevant drug(s) prior to birth

Does not insinuate impairment and may not affect outcomes for the infant

May reflect drugs administered during labor and delivery

For meconium, may reflect drugs administered directly to the newborn before specimen collection

Not detectedNo drug analytes were detected

Only the targeted drugs can be detected

Does not exclude the possibility that the mother used drugs during pregnancy

Limitations

  • The pattern and frequency of drug use by the pregnant individual cannot be determined by these tests.
  • Detection of drugs in meconium or umbilical cord tissue depends on the extent of maternal drug use, as well as drug stability in matrix, the unique characteristics of drug deposition in meconium and umbilical cord tissue, the quality and quantity of specimen submitted for testing, and the performance of the test method.
  • Concordance of results between twins is higher in umbilical cord tissue than in meconium. 
  • Minimum reporting limits and estimated concentrations are established for each compound, but quantitative results are not reported.

References