A growing number of women in Northern California are using marijuana before and during pregnancy, a group of researchers at Kaiser Permanente have found and said it coincides with broader acceptance of cannabis use and decreased understanding of potential harms.
Kaiser surveyed women during 367,400 prenatal screenings between 2009 and 2017 at facilities throughout Northern California and published the findings Friday in the Journal of the American Medical Association.
Self-reported marijuana use in the year before pregnancy increased from 6.8 percent in 2009 to 12.5 percent in 2017, and marijuana use during pregnancy rose from nearly 2 percent in 2009 to 3.4 percent in 2017.
California was one of the first to allow medical marijuana and is one of 11 that legalized recreational use in addition to decriminalizing possession of small amounts. The finding suggests that the more permissive laws have led to wider acceptance among women of child-bearing age and some women may not be aware of the risks.
“No amount of cannabis has been shown to be safe during pregnancy. We do know that it crosses the placenta and reaches the fetus,” said Kelly Young-Woff, a psychologist and researcher at Kaiser Permanente.
“There is some uncertainty about the exact risks of using cannabis during pregnancy but there is substantial evidence of an association with lower offspring birth weight and increased risk of developmental problems later on.”
What’s more, another study recently concluded that parents who used marijuana were more likely to discipline their children.
Young-Wolff said the trend is not unique to California and that the study does not conclude women continued using since many of the surveys were completed during the first 8 to 10 weeks of pregnancy.
The research builds on the previous work by Kaiser Permanente of Northern California on the subject which has shown marijuana use in pregnant women has been growing over the last decade. Another study published in JAMA last August examined marijuana use for treating nausea in pregnant women.
Young-Wolff said women may also find conflicting information online about the safety of marijuana use during pregnancy.
“There have been studies recently done showing that cannabis dispensaries are recommending cannabis products to pregnant women as a way to treat first-trimester morning sickness,” Young-Wolff said. “There is a lot of messaging that pregnant women are getting to encourage their use or give the perception that use is safe.”