3ohbzemecmcnt

Published: August 9, 2026Updated: August 16, 2026

This test checks if a newborn was exposed to cocaine during pregnancy by detecting cocaine metabolites in the baby's first stool (meconium).

Quick summary

{"Detects cocaine exposure during the last half of pregnancy","Uses baby's first stool (meconium) as sample","Helps identify babies who may need special medical care","Positive result does not mean the baby is currently addicted","Results are confidential and used for medical care planning"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC: 40901-1
Short code: 3OH-BZE Mec-mCnt
Synonyms: 3OH-BZE Mec-mCnt
Category: chemistry
Sample: serum
Container: Red-top tube (SST)
Units: N/A
Fasting: false
Population: adult
Sex: all
Age range: 18–65 years
Specimen volume: 5 mL
Stability: Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max: 500
Lipemia max: 1000
Icterus max: 500
TAT: 4–24 hours
Order: routine

What is this test?

This test looks for 3-hydroxybenzoylecgonine, which is a substance produced when the body breaks down cocaine. It is performed on meconium, which is the dark green, sticky substance that makes up a newborn's first few bowel movements. Meconium begins to form around the 20th week of pregnancy and collects substances that the unborn baby is exposed to during that time.

Why is this test done?

This test is done to find out if a baby was exposed to cocaine while in the womb. Cocaine and its breakdown products can cross the placenta and enter the baby's body. Detecting these substances helps healthcare providers give the baby the appropriate care and support they need after birth. It also helps identify families who may benefit from additional resources and support services.

What happens during the test?

The test is simple and does not cause any pain to the baby. A small sample of meconium is collected from the baby's diaper and sent to a laboratory for analysis. The sample is usually collected within the first 24-48 hours after birth. Results are typically available within a few days.

What do the results mean?

A positive result means that the baby was exposed to cocaine during pregnancy. It does not necessarily mean the baby is currently experiencing withdrawal symptoms or problems. A negative result means no cocaine exposure was detected during the testing window, though it does not rule out exposure earlier in pregnancy or to other substances.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Will my baby be taken away if the test is positive?

The primary purpose of this test is to ensure your baby receives proper medical care, not to punish families. Healthcare providers work with families to provide support and resources. Child protective services may be involved only in specific circumstances, depending on local laws and the situation.

How long does cocaine stay in meconium?

Meconium testing can detect drug exposure that occurred during the second and third trimesters of pregnancy, roughly from 20 weeks gestation until birth. This makes it a more comprehensive indicator of prenatal drug exposure compared to urine or blood tests, which only detect recent use.

Can a positive result be wrong?

While laboratory tests are highly accurate, false positives can occasionally occur. Certain medications or foods may sometimes interfere with the test. If the result is positive, healthcare providers may discuss additional testing or evaluation to confirm the findings.

Is this test required by law?

Laws regarding drug testing of newborns vary by country and state. In many places, testing is done as part of routine newborn care when there is a reason to suspect drug exposure, such as inadequate prenatal care or signs of withdrawal. Your healthcare provider can explain the specific laws and policies in your area.

Sources

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy