No link has been found between cannabis use during pregnancy and childhood problems

Two large studies looked at developmental problems and autism in children of mothers who used cannabis during pregnancy

A new study of cannabis use during pregnancy found no evidence of an increased risk of developmental delay up to 5 years or autism spectrum disorders. The study was published in JAMA Network Open.

“Our study on developmental delay is the first to examine the clinical diagnosis of speech and language disorders, motor delay, and global developmental delay and we are looking to reach 5 years, longer than other studies,” said lead author Lyndsay Avalos, PhD. MPH, research scientist with the Kaiser Permanente Division of Research (DOR).

There are many potential health outcomes for mothers and babies that are being studied related to cannabis use during pregnancy, and the findings from both studies add preliminary but growing evidence, Avalos said. The study group has previously reported potential health risks for pregnant women and poor outcomes for babies, such as premature birth.

The results from both analyzes are consistent with another recent study from the same researchers, published in the Journal of Developmental and Behavioral Pediatrics, which found no increased risk of developing a problem. of inattention or conduct problems, up to age 11, in children aged 11. mothers who used cannabis during pregnancy.

“These studies add to our limited knowledge about child development outcomes associated with cannabis use during pregnancy by using a population that is willing to study the health consequences of use. of cannabis during pregnancy,” said Avalos.

Although encouraging, the findings do not negate previous research showing a greater risk of adverse maternal and infant outcomes associated with cannabis use during pregnancy, said senior author and DOR Research Expert Scientist Kelly Young-Wolff, PhD, MPH. “We encourage pregnant people to avoid the use of cannabis during pregnancy, according to guidelines from national medical associations.”

The courses are similar in design but differ in some aspects. The childhood developmental delay paper is a retrospective study of 119,976 mother-child duos among Kaiser Permanente Northern California (KPNC) patients; children were born between 2015 and 2019 and followed for five and a half years.

For this study, the researchers looked at the patient’s medical records for a diagnosis of speech and language disorders, motor delay, or global delay. Assessments are made based on the KPNC standard assessment for developmental delay in children. Mothers were screened for cannabis use with a questionnaire and toxicology test when they started antenatal care, usually at 8 to 10 weeks. No increased risk of delay Childhood stunting has been found to be associated with the use of cannabis during pregnancy.

The second study, which focused on autism risk, included 178,948 children born between 2011 and 2019 to 146,296 KPNC patients. Child autism diagnoses were obtained from medical records and based on the KPNC comprehensive child autism diagnosis, and maternal marijuana use was assessed through prenatal care screening. The study found 3.6% of children were diagnosed with ASD. No relationship has been found with pregnant women using cannabis.

Findings from both studies could help pediatricians, said co-author Meghan Davignon, MD, a pediatric developmental physician with The Permanente Medical Group and KPNC’s regional medical director of developmental disabilities. child development. “If studies have found that children exposed to marijuana are at greater risk of developmental delay or autism, we may want to monitor these patients more,” he said. “But these results suggest that the recommended universal screening methods may be adequate.”

Reporting “negative” findings.

It’s important for epidemiologists to report null studies — when no effect is observed — so health care resources can be focused where they’re most needed, Avalos said. “For example, if we thought that the use of cannabis during pregnancy is related to autism spectrum disorder, you can use tools to identify children whose parent used cannabis during pregnancy. If it seems harmless, you can use those tools elsewhere. And you can save parents more trouble.”

Studies also advance the field by providing updated evidence based on the current use of cannabis. “While many previous studies were based on the use of cannabis by pregnant women in the 1970s, our study is based on new data that shows the potency of cannabis products used today,” he said. Young-Wolff.

Further research is needed to examine whether cannabis use later in pregnancy may be associated with an increased risk of developmental delay or autism spectrum disorders, as these analyzes are based on data on cannabis use in early pregnancy. pregnancy.

As the children in the study get older, the research team plans to look at other health outcomes that may occur later in childhood or adolescence, such as mental health problems, substance abuse and heart disease, Avalos said. said.

Findings from the work of the DOR prenatal care team are also helping KPNC’s Early Start Health program, said its regional medical director and co-author on two papers, Deborah Ansley, MD. “Women need specific information about health risks to be able to make informed decisions about drug use during pregnancy. This ongoing research project continues to produce evidence that completes the picture.”

The studies were funded by the National Institute on Drug Abuse.

Additional authors on the study of developmental delay were Nina Oberman, MPH, Stacey E. Alexeeff, PhD, Lisa A. Croen, PhD, and Sara R. Adams, MPH, of DOR; Christina D. Chambers, PhD, MPH, of the University of California, San Diego; and Kristin Steuerle, MD, of The Permanente Medical Group.

Additional authors of the autism study were Mahlet Shunkute, MS, Alexeeff, Oberman, Croen, and Adams, of DOR; and Carley Castellanos, LMFT, of Kaiser Permanente Northern California.

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About the Kaiser Permanente Division of Research

The Kaiser Permanente Division of Research conducts, publishes and disseminates epidemiological and health services research to improve the health and medical care of Kaiser Permanente members and the general public. It seeks to understand the determinants of illness and health, and to improve the quality and cost of health care. Currently, DOR’s 600-plus employees are working on more than 450 epidemiological and health services research projects. For more information, visit divisionofresearch.kaiserpermanente.org or follow us @KPDOR.