There have been numerous studies conducted, along with anecdotal evidence to both support and refute the claim that smoking cannabis during pregnancy is relatively harmless. In 2014, almost 4 percent of pregnant women said they’d recently used marijuana, up from 2.4 percent in 2002, according to an analysis of annual drug use surveys.
Now, as we enter 2017, a new report has concluded that U.S. women are increasingly using marijuana during pregnancy. Sometimes utilized as a way to prevent morning sickness, cannabis has increasingly begun to be used by some pregnant women as a way to reduce the stress associated with pregnancy.
A separate study published in the Journal of the American Medical Association found that almost 10 percent of adult marijuana users in the United States – or about 3 million people – have used cannabis at least partly for medical reasons; 20 percent of these users live in states where medical marijuana isn’t legal.
Although the actual numbers of pregnant cannabis users are small, the trend raises concerns among some because of evidence linking the drug to low birth weights and other problems. However, at this stage, such evidence would still need to be further analyzed to determine a direct correlation.
Dr. Nora Volkow, director of the National Institute on Drug Abuse, commented in an editorial in the Journal of the American Medical Association that “the results raise concerns” and urged doctors and other health care providers to avoid recommending the drug for pregnant women.
Volkow noted that laws legalizing medical marijuana in 29 states and Washington, D.C. do not list pregnancy-related conditions among allowed uses. However, the laws also don’t prohibit that use and don’t include warnings about possible harms to the fetus, she said.
Strong evidence of harms is limited, but besides low birth weights, newborns whose mothers used marijuana while pregnant may face increased risks for anemia and other problems requiring intensive care. Memory and attention problems have also been found in older children whose moms used marijuana in pregnancy, Volkow noted.
By Volkow’s own admission, the direct cause or linkage marijuana has to these problems is unclear. However, Volkow said one theory is that it might interfere with the formation of nerve cells and circuits in the brain during fetal development.
Both of these studies analyzed data from annual U.S. government surveys on drug use that are based on participants’ self-reporting.
One study focused on 200,510 women of reproductive age who participated in the 2002-2014 surveys aforementioned. Recent use – within the past month – among non-pregnant women also increased over those years, from about 6 percent to 9 percent, researchers from Columbia University Medical Center reported.
The other study, led by the drug agency’s Dr. Wilson Compton, focused on past-year marijuana use by nearly 100,000 adults aged 18 and up who participated in the 2013-14 drug survey.
About 13 percent said they had used marijuana; that translates to about 30 million adults. Overall, 90 percent used it for non-medical reasons only and 6 percent used it only for medical reasons.