NATIONWIDE -- There's a new study out suggesting that more pregnant women appear to be using marijuana, sometimes to soothe anxiety and morning sickness.

The study, published in the Journal of the American Medical Association, observed a sample of pregnant women in California.

Pot use among the study subjects climbed from 4.2 percent to 7.1 percent from 2009 through 2016.

One expert speculates that the rise might be partially explained by the increased availability of legal marijuana in recent years.

The CDC says doctors caution that marijuana's effects on a fetus aren't clear but could include low birth weight and developmental problems.