MONDAY, Aug. 27, 2018 (HealthDay News) -- In a finding that should give any new mom pause, researchers report that marijuana can linger in breast milk for almost a week.
Researchers tested breast milk samples from 50 women who used marijuana either daily, weekly or occasionally, and detected THC -- the active component of the drug -- in 63 percent of the samples for up to six days after the mother's last reported use.
"Pediatricians are often put into a challenging situation when a breastfeeding mother asks about the safety of marijuana use," said lead investigator Christina Chambers. She is a professor in the department of pediatrics in the University of California, San Diego's School of Medicine.
"We don't have strong, published data to support advising against use of marijuana while breastfeeding, and if women feel they have to choose, we run the risk of them deciding to stop breastfeeding -- something we know is hugely beneficial for both mom and baby," she explained in a university news release.
"We found that the amount of THC that the infant could potentially ingest from breast milk was relatively low, but we still don't know enough about the drug to say whether or not there is a concern for the infant at any dose, or if there is a safe dosing level," Chambers said.
"The ingredients in marijuana products that are available today are thought to be much more potent than products available 20 or 30 years ago," she added.
The study was published online Aug. 27 in the journal Pediatrics, a publication of the American Academy of Pediatrics (AAP). Meanwhile, a second troubling report in the same issue of the journal suggested that many pregnant women mistakenly believe that marijuana is harmless.
Prenatal marijuana use is on the rise in the United States, according to the AAP report. One government study found that about 2.4 percent of pregnant women had smoked pot in the past month in 2002; by 2014, that had increased to almost 4 percent.
At the same time, marijuana is being "touted" on social media as a good remedy for morning sickness, the AAP report authors noted. And as a growing number of U.S. states legalize marijuana, some women may be left with the impression that the drug is safe to use during pregnancy.
Chambers stressed that further research is needed to determine the long-term effects marijuana in breast milk has on children, specifically, if there are "any differences in effects of marijuana in breast milk for a 2-month-old versus a 12-month-old, and is it different if the mother smokes versus eats the cannabis? These are critical areas where we need answers as we continue to promote breast milk as the premium in nutrition for infants."
The Academy of Nutrition and Dietetics offers advice on what to eat and drink while breastfeeding.