Local health experts warn against using marijuana while pregnant, even as research remains inconclusive

Many questions about marijuana use during pregnancy have yet to be definitively answered by researchers, but local health officials say there’s enough information out there to justify urging mothers to lay off the drug.

“Let’s utilize some caution here, and pause, to really make people talk about it,” said Melissa Charbonneau, public health nurse with the Spokane Regional Health District’s Community and Family Services division. “Yes, it is frustrating, because you don’t have all the answers. But the answers we do have, I think, are enough to give you pause.”

That’s the thinking behind the launch several years ago of “Weed to Know,” a locally funded public education outreach by the district. The campaign is intended to reach what appears statistically to be a growing population of young mothers with less concern about using the now-legalized drug.

While marijuana use remains scarce among pregnant women and was at just 7% in 2017, according to national surveys on drug use, that figure is up from just 2.4% 15 years ago, and 3.9% in 2014, when recreational stores began opening in Washington.

The warnings the Health District posted online, and notices that now appear in those stores across the state, use language that is not definitive. Those messages warn that cannabis may affect a baby’s birth weight or interrupt the formation of cognitive abilities in their formative years, not that they will.

The campaign is supported entirely with local funding, not revenues from legal marijuana sales statewide, Charbonneau said.

There’s research to support the health statements, studies that are cited on the Health District’s website. But the participants in those studies skew toward lower-income mothers seeking health care at public facilities in other countries, and many of those mothers also used other substances, such as alcohol and tobacco, while pregnant.

Those confounding factors, as they’re known in laboratory settings, can be eliminated through statistical modeling. Celestina Barbosa-Leiker, associate dean of research at Washington State University’s Nursing School in Spokane, also is trying to avoid their influence on the question of marijuana’s effects on a fetus by speaking directly to mothers who use locally but who don’t take other substances during their pregnancies.

“The perception of cannabis has changed among pregnant women,” Barbosa-Leiker said. “These are not heroin users or polysubstance users. They were continuing use to help other chronic conditions, like chronic pain.”

Barbosa-Leiker and Charbonneau both note that major health organizations, including the American College of Obstetrics and Gynecologists and Academy of Breastfeeding Medicine, instruct health care providers to discourage marijuana use during pregnancy and breastfeeding. Multiple studies have shown that tetrahydrocannabinol (THC), the main psychoactive element in marijuana, can be passed to a child through the mother’s milk for weeks after her last use of the drug.

There’s also evidence that in the womb, THC passes through the placenta. It’s been found in the meconium, or first bowel movement, of infants born to mothers who use the drug in their third trimester of pregnancy.

There are also several unknowns that could be answered by mothers willing to speak openly about their use of cannabis in an era where the drug isn’t criminalized, Barbosa-Leiker said.

That includes the method of ingestion beyond inhaling smoke, and the first scientific studies of the effects of cannabidiol, or CBD, a non-psychoactive element that can be derived from marijuana or hemp that remains in a gray legal area nationwide.

“The studies have largely focused on smoking,” Barbosa-Leiker said. “We don’t know the impacts of all the other ways to ingest. There’s butane extraction, there’s dabbing, there’s so many other things that could also impact the fetus and the baby.”

Barbosa-Leiker said a common theme among those mothers in the study was a desire to minimize risk as a result of their use of cannabis.

“What we’re hearing from our participants is that they’re trying to make the healthiest choice for their child,” she said.

Barbosa-Leiker is in the final step of a three-phase study that’s looking at the interaction between mothers, health care providers and the marijuana retailers themselves about what advice is being given to pregnant women seeking guidance on cannabis use.

Meanwhile, a researcher at the University of Washington recently received nearly $200,000 in funding from the National Institute for Drug Abuse to recruit mothers using cannabis to treat morning sickness. The study hopes to determine, through in-utero imaging, any effect on the formation of the child’s brain. Applicants may earn up to $300 for their participation in the study.

Such research is needed in order to understand the effects of marijuana use during pregnancy and weed out the effects of other substances or recreational use as a factor in child development, said Crystal Oliver, executive director of the cannabis advocacy group Washington Sungrowers Industry Association.

“Universally, we would all like to see good research that would answer these questions,” said Oliver, who lives in Deer Park. “We can exclude things like concurrent tobacco use. That’s been a problem with a lot of the research to this point.”

Historically, research into the health effects of marijuana, and indeed any research into the drug, has been hindered by its classification under federal law as an illegal substance in all instances.

Researchers must obtain a special license from the Drug Enforcement Administration to work with marijuana, and may only obtain the drug from a single farm at the University of Mississippi. Federal legislation to reclassify marijuana in light of states legalizing its use for both recreation and medicinal uses has yet to make its way to Congress for a vote.

As research into the drug continues, the Health District will continue to urge the region’s mothers to avoid cannabis in all of its forms while both pregnant and breastfeeding. Other states that have legalized the drug are looking at Spokane’s warning language as a model for their own warnings moving forward, Charbonneau said.

“The whole thing with this was, we want to stimulate some conversation,” she said. “We don’t have all the answers, but we want people to think twice about this before I’m going to be put in charge of children, before I’m going to breastfeed my child, before I’m going to get pregnant, or even while I’m pregnant, let’s have some conversations here.”