MONDAY, Aug. 27, 2018 (HealthDay News) -- More and more pregnant or breastfeeding women are using marijuana, and U.S. pediatricians are pushing back against the notion that the drug is "safe."
There's evidence that exposure to marijuana compounds might harm the fetus, and these compounds might also find their way into breast milk, the American Academy of Pediatrics (AAP) says in a new report.
However, many pregnant U.S. women mistakenly believe that marijuana is harmless, the group said.
In fact, prenatal marijuana use is on the rise in the United States. One government study found that in 2002, about 2.4 percent of pregnant women had smoked pot in the past month; by 2014, that had increased to almost 4 percent.
Meanwhile, the AAP says, marijuana is being "touted" on social media as a good remedy for morning sickness. And as a growing number of U.S. states legalize marijuana, some women may be left with the impression that the drug is safe to use during pregnancy.
"This is becoming more of an issue as more and more states legalize medical and recreational marijuana use," said Dr. Mary O'Connor, one of the authors of the report. She's an executive committee member of the AAP Section on Breastfeeding.
The problem is: It's not yet clear what effects prenatal exposure to marijuana can have on children, according to O'Connor. It's a tricky question to study, she said, because pregnant women who use marijuana often drink, smoke or use other substances -- and it can be difficult to tease out any effects of pot, per se.
Still, studies have linked prenatal marijuana use to heightened risks of stillbirth, preterm delivery and having an underweight baby. And a couple of long-term studies have found that kids exposed to marijuana in the womb tend to have more behavioral issues and difficulty with certain mental tasks -- like planning and problem-solving.
The evidence is limited, O'Connor said, but it's enough to raise concerns.
"We recommend that women do not use marijuana while they're pregnant or breastfeeding," she said. "And we do need more research into the possible developmental effects of those exposures on children."
There is evidence that some pregnant women are using marijuana to deal with morning sickness. A study published last week found that women with morning sickness -- especially severe cases -- were more likely to screen positive for the drug.
That study, of more than 220,000 pregnant women, found more than 5 percent had recently used marijuana. Among women with severe morning sickness, the rate topped 11 percent. Of women with milder cases of morning sickness, 8 percent screened positive for marijuana.
The findings are "concerning," said the study's lead author, Kelly Young-Wolff, a research scientist at Kaiser Permanente Northern California, in Oakland.
"It's really important that we connect women with medically approved treatments for nausea and vomiting during pregnancy," Young-Wolff said.
O'Connor made the same point. "If you have morning sickness, talk to your provider about how to deal with it," she said.
Dr. Anthony Scialli, an obstetrician/gynecologist in Washington, D.C., said he's seen many women who use marijuana to ease morning sickness. And they mistakenly believe it's safe, he said.
Scialli is a member of the Organization of Teratology Information Specialists. The group runs the MotherToBaby service, which provides research-based information on the effects of medications and other exposures during pregnancy.
He said that safe, approved options for morning sickness include a combination of vitamin B6 and doxylamine, an antihistamine. Vitamin B6 and ginger is another way to go.
O'Connor said little is known about the effects of using marijuana while breastfeeding, though there is evidence that the drug can get into breast milk.
"But we don't know how much is absorbed by the baby, or what the effects might be," she said.
Breast milk is the best nutrition for babies. O'Connor said mothers who use marijuana should not stop breastfeeding -- they should stop using the drug.
Another recent study focused on marijuana dispensaries in Colorado, where medical and recreational use of pot is legal. Researchers contacted 400 dispensaries, pretending to be pregnant women with morning sickness. Nearly 70 percent of the dispensaries recommended marijuana products -- from cigarettes to edibles -- as a remedy.
One-third of them told callers that marijuana was safe during pregnancy.
O'Connor said that the people providing information at dispensaries are not necessarily health professionals. She stressed that women should get any information about marijuana and pregnancy from their doctor -- or, if they go online, to be sure they're consulting a reputable source.
The U.S. Centers for Disease Control and Prevention has more on marijuana use and pregnancy.