Several soaps used to wash newborn babies may cause the baby to test positive for marijuana on some screening tests, according to a new study.
Urine samples that had tiny amounts of any of five popular baby soaps — Johnson’s Head-To-Toe Baby Wash, J&J Bedtime Bath, CVS Night-Time Baby Bath, Aveeno Soothing Relief Creamy Wash and Aveeno Wash Shampoo — gave a positive result on a drug screening test for tetrahydrocannabinol (THC), the principal psychoactive ingredient in marijuana, reports Rachel Rettner at MSNBC.
The researchers began investigating after nurses at one North Carolina hospital reported a big increase in the number of newborns testing positive for marijuana. The amount of soap in the urine needed to produce a false positive test result was tiny, less than 0.1 milliliters, according to the researchers.
This is a big deal, because screening tests that show a baby has been exposed to marijuana can, and often do, lead to the involvement of social services and even law enforcement due to accusations of child abuse. In one Alabama case last year, for example, a mother was arrested and criminally charged with “chemically endangering” her child when her baby boy tested positive for marijuana.
This, despite the fact that the body’s own cannabinoids — chemically almost identical to the active ingredients of cannabis — are naturally present in mother’s milk, and are crucial for the baby’s development. In addition, according to the best scientific research, marijuana use by pregnant women may actually reduce infant mortality. Also, the babies of pot-smoking mothers scored better on tests of cognition than babies of non-toking mothers, besides.
But meanwhile, back to the false marijuana positives caused by soap on babies. Given the consequences, healthcare providers and laboratory staffs should be made aware that these soaps — and possibly others — can lead to a positive rest for cannabis. For that reason, positive tests should ideally be confirmed by a more sensitive method, the researchers said.
“We really did this to help protect families from being falsely accused” of marijuana use, and to help ensure that “intervention” efforts are directed at babies who are actually at risk of drug exposure, said study researcher Dr. Carl Seashore, who’s a pediatrician in the newborn nursery at the University of North Carolina – Chapel Hill.
Drug screening tests in hospitals that come back positive are usually not sent out to labs for additional confirmation, because of the time and expense, said study researcher Catherine Hammett-Stabler, also of UNC Chapel Hill.
It’s become more and more common to screen newborns for marijuana exposure, and is considered “especially recommended” for babies born to women thought to be “high risk” for “drug use,” such as those who don’t come in for prenatal care visits, according to Hammett-Stabler. About 10 to 40 percent of babies born at UNC Chapel Hill hospital receive the test each month, according to Seashore.
The researchers said they aren’t sure why the soaps would cause positive marijuana tests. It could be that some compounds in the soap are chemically similar to THC (this doesn’t mean you need to go smoking soap), or it could be that the chemicals in the soap change the way the test works, according to Hammett-Stabler.
When a more sensitive test was used on the urine samples containing the soap, the test came back negative, Hammett-Stabler said.
UNC Chapel Hill, at least, has changed its policy based on its own findings. All positive newborn drug urine tests from the hospital are now sent out for confirmation before any action is taken.
The study was published in the June issue of Clinical Biochemistry.