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 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.
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 specific subgroups of pregnant women, including black women, women ages 26 to 44 and those who did not finish high school.
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.