Most of the dispensaries ultimately told the women to get advice from a healthcare provider, but this was usually only after the researchers prompted them to do so.
The state's cannabis retailers sold $106 million in flower, edibles and concentrate for adult-use purposes during March, according to data released Wednesday by the Colorado Department of Revenue.
But the remainder outright asserted that marijuana is safe during pregnancy, although the American College Of Obstetricians and Gynecologists and the American Academy of Pediatrics disagree, saying doctors should discourage women from marijuana use while pregnant or breastfeeding.
"We do know that THC crosses into the placenta and so if a woman is using marijuana during pregnancy it does cross to the fetus, so it's definitely plausible that there would be effects on the fetus", Metz said.
Out of those who said using marijuana would be OK, 65 percent said their recommendations were based largely on their opinion, starting by saying things like "personally".
In the recent Colorado study, Dr. Metz and her fellow researchers reported a huge variance in the recommendations given from dispensary employees to pregnant women. Since using cannabis use does not consistently result in the same visible birth defects caused by alcohol, tobacco, or hard narcotics, reports demonstrate that some women do not consider the potential long-term effects of consuming weed while pregnant.
"Google is first. Then if you feel apprehensive about it, you could ask", said one dispensary's employee. "All the studies done back in the day were just propaganda", said another employee at another dispensary.
"Maybe you have a progressive doctor that will not lie to you. Are there any products that are recommended for morning sickness?"
"First line medical therapy for treatment of nausea and vomiting in pregnancy is vitamin B6 and doxylamine", Metz told Reuters in an email.
Kristi Kelly, the group's executive director said, "What this tells us as an industry is that we have a gap in our 'onboarding process, ' in terms of training our dispensary workers to provide not just a good conversation on products, usage and dosing... but it's very important that employees clarify they are not medical professionals and that they also redirect that patient or customers to also have a conversation with their health care professional".
Still, experts say the science is still in progress, and human studies are primarily observational: "It is unethical to purposely expose women and their unborn babies to marijuana during pregnancy to study outcomes", Mark said.