MY TURN: The case for protecting Idaho’s babies: What the science says about cannabis and pregnancy

When I was a student at Eastern Washington University, I read a series of articles ringing early warning bells regarding significantly rising rates of birth defects reported in Colorado immediately following the legalization of recreational marijuana. The idea that legal cannabis could inadvertently put developing babies at risk was the subject of my Anthropology Senior Thesis. Today’s historical trends and research reinforce that concern, supported by data from large, well-designed studies. 

An NIH-funded study published in The Journal of the American Medical Association (JAMA) found that pregnant individuals with cannabis exposure (confirmed by urine drug tests) had a much higher rate of adverse outcomes compared with those not exposed, 25.9% vs 17.4%. It includes small-for-gestational-age birth, preterm delivery and hypertensive disorders. 

A comprehensive meta-analysis of 51 studies involving more than 21 million births found that prenatal cannabis use was associated with: 

• 75% higher odds of low birth weight, 

• 52% higher odds of preterm birth, 

• 57% higher odds of small-for-gestational-age infants (even after adjusting for other factors such as tobacco use)

These outcomes are medically significant because they are strongly linked to a greater risk for childhood disability, chronic health problems and developmental delays. Other research shows that prenatal cannabis use is associated with increased risk of gestational hypertension, placental abruption and need for admission to neonatal intensive care units. 

A recent large cohort study found associations between maternal prenatal cannabis use and specific structural birth defects, including omphalocele (an abdominal wall defect). It was a particular focus of my Senior Thesis Paper. Unlike alcohol, which is rapidly metabolized, THC (tetrahydrocannabinol), the psychoactive compound in marijuana, can remain in the body for weeks. THC crosses the placenta, entering fetal circulation early in pregnancy, even before many pregnant individuals know they are pregnant. This prolonged exposure increases the window of potential impact during critical stages of fetal development when organs and the brain are forming. The American College of Obstetricians and Gynecologists (ACOG) explicitly compared the unknown risk levels for cannabis with alcohol, noting that “no amount of cannabis has been shown to be safe during pregnancy.”

Are you now wondering about recent trends in Colorado? Following the legalization of recreational cannabis, researchers documented a more than two-fold increase in cannabis-involved pregnancy hospitalizations, including a four-fold rise in hospitalizations per 10,000 live births. 

While not all increases in hospitalizations equate directly to birth defects, these trends do indicate that cannabis use during pregnancy became far more common in the legal market context, and medical systems saw this reflected in increased complications. 

Based on the growing body of data, it is clear that prenatal cannabis exposure is not benign. Associations with low birth weight, preterm delivery, structural abnormalities and other serious outcomes have been observed repeatedly across large, peer-reviewed studies. These risks are not just speculative; they reflect real health concerns with historical data demonstrating devastating outcomes. 

For the health and safety of Idaho’s babies, policymakers and voters should carefully weigh this evidence before supporting any measures that would expand access to or normalize recreational marijuana use. Please help ensure that we prioritize the protection of women and their infants. 

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Nicole Barnett is a Hayden resident.