(CNN) — More expectant mothers than ever are smoking pot.
A new study published in the Journal of American Medical Association found that in 2017, 70 percent of future moms in the U.S. admitted to using marijuana while expecting.
That’s more than double compared to 15 years earlier.
The pot usage is the highest in the first trimester, when a fetus is most vulnerable. And a vast majority of those women used pot without a doctor’s recommendation.
There’s no clear-cut answer as to how pot affects a fetus, but the CDC says marijuana could lead to developmental problems and low birth weight.