Certain soaps used to wash babies shortly after birth may cause the baby to test positive for marijuana on some newborn screening tests, a new study suggests.
In the study, urine samples that contained minute amounts of any of five baby soaps — Johnson & 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 active ingredient in marijuana.
The researchers began their investigation after nurses at a North Carolina hospital reported an increase in the number of newborns testing positive for marijuana.
The amount of soap in the urine needed to produce a positive test result was tiny, less than 0.1 milliliters, the researchers said.
