A Colorado proposal to require warning signs aimed at pregnant or nursing women at pot shops was rejected Tuesday, but the suggestion renewed debate about how to approach maternal marijuana use.
The bill would have required dispensaries to post signs warning about "dangers to fetuses caused by smoking or ingesting marijuana while pregnant."
Pot shoppers in Colorado and Washington already receive warnings that the drug shouldn't be used by pregnant and nursing women. The new proposal would have added signs and banned employees from recommending medical marijuana to a pregnant woman.
Republican Rep. Jack Tate said he sponsored the bill after hearing of pregnant women using marijuana to treat nausea and vomiting.
"It is very, very important for women to be informed consumers when making health care decisions," Tate said.
But he agreed to scrap the effort Tuesday and try again after his proposal revived an ongoing debate about maternal marijuana use.
Sadie Lane, chapter leader for Colorado Foothills Moms for Marijuana, testified that she used pot while pregnant and that women need to talk to doctors, not pot-shop operators, about using the drug while pregnant.
"Show them both sides and let them make the decision with their doctor," Lane said.
A report issued by the Colorado Department of Public Health & Environment this week notes that marijuana's psychoactive ingredient, THC, is passed to children through the placenta and breast milk. But the doctors who compiled the survey of existing research also noted that the health consequences of that THC exposure aren't fully understood.
The report's authors found:
— "Mixed" evidence for pot's link to birth defects.
— "Insufficient" evidence that marijuana use during pregnancy makes offspring more likely to use pot themselves as adolescents.
— "Moderate" evidence that maternal use of marijuana during pregnancy is associated with attention problems, cognitive impairment or low IQ in offspring.
— "Mixed" evidence that marijuana use during pregnancy is associated with low birth weight.
Still, the doctors concluded, "There is no known safe amount of marijuana use during pregnancy."
The report, released Monday, reflected national conclusions on marijuana's health risks.
An American Academy of Pediatrics report in 2013 listed marijuana among the most common drugs involved in prenatal exposure that may pose important health risks, including possible behavior and attention problems in childhood.
The National Institute on Drug Abuse says animal studies have suggested that smoking marijuana in pregnancy may harm brain development. But the institute also says more research is needed "to disentangle marijuana's specific effects from other environmental factors, including maternal nutrition, exposure to nurturing/neglect, and use of other substances by mothers."
Colorado, one of four states that have legalized recreational use of pot, requires marijuana to carry labels saying, among other things, "There may be additional health risks associated with the consumption of this product for women who are pregnant, breastfeeding or planning on becoming pregnant."
In Washington state, marijuana purchasers are given written warnings that include, "Should not be used by women that are pregnant or breastfeeding."
Tate said he'll try again to require additional pregnancy warnings, a concept backed by the Colorado Medical Society.
Tate conceded that more needs to be known about maternal marijuana use, but that lack of research shouldn't prevent warnings.
"Uncertainty means risk," Tate said.
"The burden of proof must be placed on the case that marijuana is safe, rather than that marijuana is harmful."
Kristen Wyatt can be reached at http://twitter.com/APkristenwyatt . Associated Press writer Lindsey Tanner in Chicago contributed to this report and can be reached at http://twitter.com/LindseyTanner .
House Bill 1036: http://bit.ly/1KliNtU
Colorado health survey: http://1.usa.gov/1z74ClA