Prenatal cannabis use does not increase the risk for developmental delays in children

Key takeaways:

• Developmental delays were not associated with prenatal cannabis use nor the frequency of use.
• Pregnant individuals should still avoid cannabis use because of other adverse health outcomes, a study author said.

Cannabis use among women during early pregnancy did not correspond with an increased risk for early developmental delays in children, a cohort study published in JAMA Network Open showed.

“Over the past decade or so, as legalization of cannabis has risen across the U.S., we have seen a rise in prenatal cannabis use,” Lyndsay A. Avalos, PhD, MPH, a research scientist at Kaiser Permanente Northern California Division of Research and the study’s lead author, told Healio.

“Also, some pregnant individuals report using cannabis to treat conditions during pregnancy such as nausea and vomiting or depression, as they think cannabis may be a safe and more natural alternative to pharmaceutical medications during pregnancy,” she added. “Despite animal studies finding that cannabinoids can freely cross the placenta and enter the fetal blood stream with potential to disrupt fetal neurodevelopment, very little is understood about the potential longer term effects of prenatal cannabis use on child neurodevelopment.”

Avalos and colleagues examined a cohort of 119,976 children born to 106,240 people between January 2015 and December 2019 and who were followed up to the age of 5.5 years or younger through Dec. 31, 2021.

The study used self-reported maternal prenatal cannabis use via a self-administered questionnaire or measured through urine toxicology testing.

Results showed an overall maternal prenatal cannabis use rate of 5.6% for all pregnancies.

Avalos and colleagues found no associations between maternal prenatal cannabis use and:

• child speech and language disorders (HR = 0.93; 95% CI, 0.84-1.03);
• global developmental delays (HR = 1.04; 95% CI, 0.68-1.59); and
• motor delays (HR = 0.86; 95% CI, 0.69-1.06).

The frequencies of maternal prenatal cannabis use also did not affect the risk for developmental delays.

Avalos noted that the findings “were consistent across multiple sensitivity analyses, including the exclusion of participants with other prenatal substance use.”

The results, while reassuring, “do not negate the body of evidence linking prenatal cannabis use to an increased risk of adverse maternal, fetal and neonatal health outcomes,” Avalos underlined.

“Physicians should follow guidelines by the American College of Obstetrics and Gynecology and American Academy of Pediatrics and continue to educate pregnant individuals and those considering pregnancy on the known adverse health effects linked to prenatal cannabis use, prioritizing nonstigmatizing and supportive counseling,” she said.

Avalos concluded that more analyses are needed to further understand the possible effects of prenatal cannabis use on children development.

“Our study evaluated prenatal cannabis use at one time in early pregnancy. Further research should evaluate cannabis throughout pregnancy and explore whether continued use or longer duration is associated with an increased risk of child developmental delays,” she said. “Additionally, we did not have information on the route of administration, such as vaping or smoking, or the potency of the cannabis product, which has been steadily increasing over time. Future studies should collect this information to explore whether these factors are linked to an increased risk of developmental delays in children.”

References:

• Avalos L, et al. JAMA Netw Open. 2024;doi:10.1001/jamanetworkopen.2024.40295.
• No link found between prenatal cannabis use and early childhood disorders. Available at: https://divisionofresearch.kaiserpermanente.org/blog/2024/10/18/no-link-prenatal-cannabis-use-early-childhood-disorders/. Published Oct. 18, 2024. Accessed Oct. 28, 2024.