Is It Safe To Use Cannabis While Pregnant? New Study Suggests It Can Cause Aggression & Anxiety In Children

As cannabis becomes more accepted and its legal use widespread, more and more women report they are consuming marijuana during pregnancy. And while there’s more and more scientific evidence on the many medical benefits of the plant, one thing is certain, moms-to-be need more education on safe cannabis use during pregnancy. 

Alcohol is legal, right? But it’s strongly recommended that pregnant women refrain from imbibing.

Previously, researchers discovered a connection between cannabis use during pregnancy with autism and childhood psychosis. Now, a new study adds several more serious health conditions to that list, reported CNN Health.

U.S. researchers conducted a small study published in the journal, Proceedings of the National Academy of Sciences that looked at 322 mother-child pairs in New York City as part of a much larger project on stress in pregnancy. The study revealed that cannabis use during pregnancy can affect the placenta and may be connected to higher levels of anxiety, aggression and hyperactivity in children. 

The study examined hormone levels from hair samples in children aged three to six, measured heart function and surveyed parents on children’s behavioral and emotional functioning. The researchers also checked placental tissue collected at the time of birth from some of the study participants.

"This new study supports a growing body of evidence that smoking cannabis during pregnancy is associated with adverse outcomes for women and their children," Dr. Daghni Rajasingam, consultant, obstetrician and spokesperson for the Royal College of Obstetricians and Gynaecologists in the UK, told the Science Media Centre in London.

"We know from previous studies that using cannabis during pregnancy is linked to impaired fetal brain development, stillbirth, low birth weight, and pre-term birth. This new evidence adds to these existing safety concerns, suggesting that cannabis use in pregnancy could lead to higher anxiety, aggression, hyperactivity, and levels of the stress hormone cortisol in the children," Dr.  Rajasingam said.

Immunosuppression In The Placenta

Placental tissue evaluation also showed that marijuana consumption during pregnancy is connected with lower expression of immune-activating genes, such as cytokines, which help protect from pathogens.

The results indicate that immunosuppression in the placenta caused by maternal marijuana consumption may increase the risk of mental health problems in children such as higher anxiety, wrote CNN Health.

Nevertheless, the authors of the study said that the complete effect of maternal cannabis use on the immune system cannot be evaluated from placental gene expression alone.

"We know that cannabinoid signaling plays a role in modulating stress, which is why some people use cannabis to reduce anxiety and relax," said Yoko Nomura, a psychology professor at City University of New York's Queens College and Grad Center who was first author on the paper.

"But our study shows that in utero exposure to cannabis has the opposite effect on children, causing them to have increased levels of anxiety, aggression, and hyperactivity compared to other children who were not exposed to cannabis during pregnancy," Nomura said in a press release.

The study also considered other factors that could clarify the connection between maternal cannabis use and anxiety, hyperactivity and aggression, such as parent’s age, marital status, education, the child’s gender, age and ethnicity. 

The authors highlighted that considering that this was a “human study” it had many limitations, such as not being able to get accurate data on the history of cannabis use or to separately research prenatal and postnatal marijuana consumption.

“Also, we cannot control for various confounds (e.g., lifestyle, parenting, genetics, etc) and would need a study of thousands of individuals to determine the relevance of various factors to the outcome measures," said study author Yasmin Hurd, Ph.D., the Ward-Coleman Chair of Translational Neuroscience and director of the Addiction Institute at Mount Sinai.

"Although cannabis is considered a safe drug, it can have negative long-term outcomes on children. Speak with your doctor ... to find ways to potentially alleviate morning sickness or anxiety while pregnant."

Hurd added, “It’s not that I think that cannabis is a horrible thing. But it is a drug that we need to make sure we understand which individuals may be more vulnerable.”

Photo: Courtesy of Ryan Franco on Unsplash