April 1, 2022: Should Urine Drug Screens be routinely obtained on all pregnant women? If they are positive, then what?


Next abstract from the American College of Medical Toxicology Meeting.

The American College of Obstetrics and Gynecology (ACOG) recommends using a questionnaire to screen all pregnant women regarding drug use. ACOG does not recommend routine urine drug screens (UDS).

This group of investigators analyzed discarded urine from 400 pregnant patients. They obtained two samples from each patient. They excluded patients with substance abuse disorder.

In 800 samples, 48 psychoactive substances, prescription meds, or drug metabolites were found. They then performed a descriptive analysis of the results.

Number of samples positive for: (these are the most frequent positives)
• Methamphetamine-10 samples
• Benzoylecgonine (metabolite of cocaine)-11 samples
• 30.5% of samples were positive for THC ( marijuana) metabolite—Remember the THC metabolite can be present in urine for days after smoking-especially if repeated smoking has occurred.

This came from a large clinic in Missouri and may not be generalizable, but it is still a much higher incidence of positive UDS than most of us would imagine.  In that state, a positive UDS during pregnancy (including THC)  is considered child abuse and must be reported to the Dept of Health. Physicians are hesitant to report the positive THC screens due to the many testing issues regarding THC and the potential removal of the child as a result of the positive test. Some Ob/GYNs are considering removing THC from UDS.    

Tennessee Laws Regarding Pregnancy and Drug Use

In Tennessee in 2014, the Public Chapter 820 “Fetal Assault Law” was passed which made substance use during pregnancy a prosecutable crime in Tennessee. Over 100 women were arrested in the two-year trial period until the “Fetal Assault Law” ended on March 23, 2016. Many of those cases have been overturned and Public Chapter 820 has not been replaced with another law. There is no current statute on the books that makes substance use during pregnancy a prosecutable crime in Tennessee. Health Care Providers are not required to report positive UDS tests in pregnant women.

Comment: As the specialty of Addiction Medicine grows, the ED has rapidly become a place to identify people with substance abuse disorder and start potential treatment/referral. Understanding the issues relating to ED patients with substance abuse disorder will become necessary to care for these patients.

Question prepared by Donna Seger, MD

From last week: The following statement in the last Question of the Week on the Adverse Effects of ivermectin:

The above AEs occurred as a result of self-treatment and self-medication with a drug not intended for human use.

Generated a comment from three of our readers who noted that Ivermectin is used in humans.

Quite right. According to the CDC website, Ivermectin is a medication that is approved by FDA in oral formulations to treat onchocerciasis (river blindness) and intestinal strongyloidiasis. Topical formulations are used to treat head lice and rosacea.

But the medications used for animals are not the same formulation prescribed for humans. The size of the dose of the pills is very different and animal products may also contain excipients that have not been evaluated for use in humans.

The following statement would have been more accurate:

The AEs occurred as a result of self-treatment and self-medication with a drug formulation not intended for human use.

Thanks to the readers who read the Question so carefully.


I am interested in any questions you would like answered in the Question of the Week. Please email me with any suggestions at donna.seger@vumc.org.


Professor Emeritus
Department of Medicine, VUMC

Tennessee Poison Center
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