Slight risk of ADHD in children of pregnant women who smoke cannabis, study shows

The number of Israelis using medical cannabis for pain and other medical conditions has reached 140,000, giving the country the highest rate of use per capita in the world – three decades after the Health Ministry released its first official medical license for it.

In three more years, this number is forecast to reach almost a quarter of a million patients – an increase of more than 70% – the result of reforms being prepared that will make it easier for patients to purchase it. Even now, almost every pharmacy in the country sells the drug to all who present a ministry license.

As some users are pregnant women, there has been concern among pediatricians and other specialists that if they use medical cannabis while pregnant – even before they know they have conceived – it could cause long-term damage to their children.

Now, a study led by Prof. Ilan Matok and Hely Bassalov, who has a bachelor’s degree in pharmacy from the Clinical Pharmacy Department of the School of Pharmacy in the Hebrew University of Jerusalem’s Faculty of Medicine, reveals only subtle differences in the neuropsychiatric risks of prenatal cannabis exposure. They were assisted by Prof. Omer Bonne and Dr. Noa Yakirevich-Amir from the Psychiatry Department of the Hadassah-University Medical Center in Jerusalem’s Ein Kerem.

Just published in the American Journal of Obstetrics and Gynecology under the title “Prenatal cannabis exposure and the risk for neuropsychiatric anomalies in the offspring: a systematic review and meta-analysis,” the research found a slight increase in the risk of attention-deficit hyperactivity disorder (ADHD) and a heightened vulnerability to cannabis use in offspring. These results highlight the need for continued caution and further investigation into the long-term effects of cannabis use during pregnancy.

“Our research marks a significant step forward in understanding the complex relationship between prenatal cannabis exposure and neuropsychiatric outcomes in children. As the legal landscape surrounding cannabis continues to evolve, studies like this will be essential in guiding public health recommendations and ensuring the well-being of future generations,” they declared.

The prevalence of its use among pregnant women is also on the rise, raising concerns about its impact on fetal development.

“These findings suggest that while prenatal cannabis exposure does not appear to significantly increase the risk for many neuropsychiatric disorders, there is still a mild increase in the risk for ADHD and a greater likelihood of cannabis use in the offspring,” Matok commented. “This calls for cautious interpretation, as it does not confirm the safety of cannabis consumption during pregnancy.”

Importance of continued research

The study emphasizes the importance of continued research in this area, especially given that most of the studies on the subject were conducted between the 1980s and early 2000s when cannabis was characterized by considerably lower Δ9-THC content than cannabis used today. Therefore, findings presented in the current study may potentially underestimate the impact of contemporary prenatal cannabis exposure on long-term neuropsychiatric outcomes.

“While our study provides important insights, it is crucial to recognize that these results are not definitive. Pregnant women should be aware of the potential risks, and healthcare providers should continue to advise caution when it comes to cannabis use during pregnancy,” added Matok, who said cannabis is being taken increasingly for recreational use.

Existing recommendations published by the American College of Obstetricians and Gynecologists and the American Academy of Pediatrics state that any medical and recreational cannabis consumption in pre-conception, pregnancy, or breastfeeding should be discouraged.