Part of the reason why marijuana still being a controlled substance is super lame is that it makes it a lot harder than it should be to perform medical research on the stuff. Though people have been smoking reefer since time out of mind, most medical data on it is pretty recent and often times unconfirmed.

Using cannabis while pregnant is generally frowned on (some mothers who use have had their children taken away from them by child protection services), but not all that much is known about marijuana’s effect on fetal children. Which is why the new study from medical researchers at the University of Colorado could do wonders for clearing up whether pot use could help, harm, or have virtually no effect on pregnant women and their unborn children.

Obstetrician Dr. Torri Metz will use money from a grant to do a quantitative study of pregnant women and their cannabis use, according to The Cannabist. Part of the research will involve a questionnaire given to new mothers.

“If you look at the literature now, you find very mixed results,” Metz said. “About half of the studies say there is an association between marijuana use and adverse outcomes. About half say there is no association.”

“I am seeing more and more self-reported marijuana use in the clinic,” she said. “I don’t know if this is a reflection of women using more marijuana or of the women being more willing to tell us about their use.”

Some say that weed can be a healthier, less expensive alternative to medicines which are prescribed to mitigate symptoms of morning sickness. “I was initially against the idea of it, mainly because of the stigma surrounding smoking while pregnant,” one anonymous mother told VICE. “However, after three weeks of keeping almost nothing down and craving a sandwich… I smoked for the first time. Just a couple hits. I sat back, ate half a sandwich, and it didn’t come back up!… When I smoked, I could eat and nap. It helped keep food down and was better than Zofran [a leading prescription medication for morning sickness].” But another study says that THC “is known to cross the placenta,” which could lead to a decrease in birth weight.