In the study, 50 women who reported using cannabis supplied breast milk samples to Mommy’s Milk, a human milk research lab at the University of California, San Diego. The women also filled out a questionnaire with information about the use of cannabis and other medications during the 14 days prior to giving the samples.
Analysis of the samples showed the presence of THC in 34, or 63 percent, of the 54 samples. Five of the samples, or 9 percent, had detectable levels of CBD. THC was detected in samples up to six days after reported cannabis use.
Christina Chambers is a professor of pediatrics at UCSD, the director of clinical research for the Department of Pediatrics at UCSD and Rady Children’s Hospital in San Diego and one of the study’s senior authors. She said that the effect the cannabinoids may have on a developing fetus has not been determined.
“Whether this means that some level—or any level—of these metabolites can negatively influence child development is unknown at this point,” Chambers said.