DENVER — Colorado lawmakers struggling to make sense of incomplete scientific evidence about marijuana use by pregnant and nursing women have scrapped a bill to add warnings in pot shops about maternal marijuana use.
Lawmakers rejected a bill that would have required dispensaries to post signs warning about “dangers to fetuses caused by smoking or ingesting marijuana while pregnant.” They heard testimony from women who used marijuana to treat nausea during pregnancy, but also from doctors who called for additional warnings.
Republican Rep. Jack Tate vowed to try again to craft additional warnings after hearing of pregnant women using marijuana.
“It is very, very important for women to be informed consumers when making health care decisions,” Tate said.
But lawmakers also heard from women who said existing warnings are adequate. Colorado and Washington state, the first states with recreational pot stores, both require shoppers to get written warnings that include suggestions pregnant and nursing women should avoid pot.
Sadie Lane, chapter leader for Colorado Foothills Moms for Marijuana, testified that she used pot while pregnant and 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.”
The Colorado Medical Society backed Tate’s bill and expanded warnings in an abundance of caution.
“We’re just opening the door on research” about maternal marijuana use, said Dr. Brent Keeler.