More Women Are Using Marijuana During Pregnancy, Report Says

Fewer women are smoking cigarettes and drinking alcohol during pregnancy, but more are using marijuana, according to new federal data.

Between 2002 and 2016, the percentage of pregnant women who reported smoking cigarettes while expecting fell significantly: from 17.5% to about 10%, according to a research letter published Monday in JAMA Pediatrics. Alcohol use also fell modestly during this time period, from nearly 10% to about 8.5%. But cannabis use among pregnant women — while still relatively rare — is on the rise, increasing from almost 3% of pregnant women to almost 5%.

Those figures were based on responses to the National Survey of Drug Use and Health. About 12,000 pregnant women ages 18 to 44 responded to the survey between 2002 and 2016; roughly 3,500 of these women were in their first trimester of pregnancy, a critical time for fetal development.

While the new paper did not assess the reasons behind substance use trends, the uptick in cannabis use likely has to do with relaxed marijuana laws across the country. Medical marijuana is now legal in the majority of U.S. states, while recreational marijuana use is legal in nine states, which has fueled a significant increase in the number of Americans who report using the drug. (The researchers note that past studies have come up with different rates of marijuana use during pregnancy, likely because of differing study methodologies; even still, the recorded trends are similar.)

Meanwhile, the decline in smoking cigarettes while pregnant corresponds with an overall decrease in the number of Americans who smoke. The percentage of smokers in the U.S. hit a new low recently, dropping from 45.1 million cigarette users in 2005 to 36.5 million, or about 15% of the population, in 2015. The researchers did find, however, that decreases in smoking were less pronounced among certain subgroups of pregnant women, including black women, women ages 26 to 44 and those who did not finish high school.

Alcohol use has remained fairly steady in recent years, both among pregnant women and American adults in general. While research shows that heavy drinking during pregnancy is associated with infant health risks, namely fetal alcohol disorder, experts are still divided on the acceptable amount of drinking for pregnant women. Some doctors maintain that they should not drink at all, and others suggest that light drinking is likely safe.

There is far less research on the health effects of marijuana, but in general, the CDC and other public health organizations have warned expectant mothers not to use the drug while pregnant, due to potential developmental harms for infants. Similar warnings exist for smoking cigarettes while pregnant.

The authors of the new paper echoed these warnings. “Greater public awareness regarding the consequences of prenatal cannabis exposure in offspring health is necessary,” they write.