The offspring of lab rats that were exposed to marijuana smoke during pregnancy took longer to learn and comprehend tasks than rats whose mothers weren’t exposed to THC, researchers found.
At Washington State University, researchers placed pregnant rats in a small transparent chamber, and 60 times a day, for 2 minutes at a time, the moms-to-be got hit with a blast of vaporized cannabis extract.
Photographs show the white haze, sometimes shooting right at the nostrils of the curious animals, sometimes engulfing their tiny heads. The female rats began getting stoned during the week of their mating period, and then for the 21 days of gestation.
The results were another warning for mothers-to-be who like to light up. The offspring of the rats that ingested marijuana during pregnancy showed slowed development. Or, in layman’s terms, “It was like something wasn’t clicking with them,” explains Ryan McLaughlin, an assistant professor in WSU’s Department of Integrative Physiology and Neuroscience.
Although only a small percentage of pregnant women say they smoked pot in the past month, their use has dramatically increased, according to a 2017 study in the Journal of the American Medical Association.
Nationally, it has jumped by 62 percent from 2002 to 2014, to 4 percent of total pregnant women.
In Washington, the discharge papers for pregnant women staying at hospitals — presumably for delivery but perhaps other reasons — indicate whether they had used drugs. The number of moms who said they had used marijuana but not any other drugs has “been steadily rising,” says a 2016 report by the state’s Health Services Research Project.