Prenatal Cannabis: Does It Affect Childhood Development?

Cannabis use during pregnancy is rising, with many expecting mothers turning to it as a remedy for nausea, pain, and anxiety. However, emerging research suggests prenatal cannabis exposure may have lasting consequences on childhood development, particularly in cognitive function and behavioral regulation. A recent study published in JAMA Pediatrics explores the impact of maternal cannabis use on young children’s executive function and aggression, raising questions about the potential long-term effects of prenatal exposure.

Prenatal Cannabis Use: A Growing Trend

Cannabis use among pregnant individuals in the U.S. has more than doubled over the past two decades. In 2002, an estimated 3.4% of pregnant women reported using cannabis. By 2021, that percentage had climbed to 7.2% (National Institute on Drug Abuse, 2022). Several factors contribute to this increase, including the rising social acceptance of cannabis, the legalization of recreational and medicinal marijuana in many states, and the perception that cannabis is a safer, "natural" remedy for pregnancy-related symptoms like nausea, anxiety, and insomnia.

Despite these perceptions, many health organizations—including the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists—warn against cannabis use during pregnancy. The primary concern is that tetrahydrocannabinol (THC), the psychoactive component in cannabis, crosses the placenta and can affect fetal brain development.

Cognitive and Behavioral Effects of Prenatal Cannabis Exposure

Recent studies indicate that prenatal cannabis exposure may interfere with key neurodevelopmental processes, leading to cognitive difficulties in young children. Executive function—a set of mental skills essential for problem-solving, planning, and self-regulation—appears to be particularly vulnerable to prenatal THC exposure.

A study by Keim et al. (2024) found that children exposed to cannabis in utero performed worse on tasks measuring attention span, impulse control, and cognitive flexibility. These deficits could have long-term implications, as executive function is a crucial predictor of academic success, emotional regulation, and social competence.

How Does Cannabis Affect Brain Development?

The developing brain undergoes rapid changes during fetal growth, with the endocannabinoid system playing a significant role in neurodevelopment. THC interacts with cannabinoid receptors in the brain, which can disrupt normal signaling pathways. This interference may contribute to alterations in cognitive processing, memory formation, and behavioral regulation.

Disruptions in neural development may explain why children with prenatal cannabis exposure struggle with tasks that require sustained attention, flexibility in thinking, and inhibition of impulsive reactions.

The Link Between Prenatal Cannabis Exposure and Aggression

Another alarming finding is the association between prenatal cannabis exposure and increased aggression in young children. The study published in JAMA Pediatrics used observational experiments—such as the Bobo Doll experiment—to assess aggression levels. Children exposed to cannabis during pregnancy exhibited more aggressive behaviors, such as hitting the doll with a closed fist and demonstrating reduced impulse control.

Aggressive behaviors in early childhood can lead to difficulties in peer relationships, challenges in school settings, and an increased risk of behavioral disorders later in life. Researchers suspect that prenatal cannabis exposure may disrupt the development of the brain’s frontal lobe, a region responsible for impulse control and emotional regulation.

Assessing Developmental Challenges: New Study Methods

Unlike previous studies that relied heavily on caregiver-reported behavior, recent research takes an objective approach to evaluating childhood cognitive and behavioral function.

Objective Measurements vs. Parental Reports

Traditional studies on neurodevelopmental effects often depend on parental questionnaires and reports, which can be subjective or influenced by bias. However, the latest research utilized lab-based cognitive tests and structured behavioral observations to assess executive function and aggression more objectively.

Key methods included:

• Computerized cognitive assessments measuring attention span, problem-solving ability, and impulse control.
• Structured observational experiments to evaluate aggression and social behavior in controlled environments.
• Neuroimaging techniques (in future studies) to examine structural changes in the brain related to prenatal cannabis exposure.

Findings from these studies indicate that while caregivers may not always report noticeable behavioral differences, laboratory assessments reveal significant cognitive challenges and increased aggression in cannabis-exposed children.

What This Means for Long-Term Childhood Development

Deficits in executive function and increased aggression may have far-reaching consequences for childhood development. Adverse effects on attention, impulse control, and behavioral regulation can:

• Lead to academic struggles due to difficulty concentrating, following instructions, and problem-solving.
• Increase the likelihood of emotional difficulties, such as anxiety or frustration in social situations.
• Contribute to behavioral issues that affect interactions with peers and authority figures.

While current research focuses on children around the age of five, future longitudinal studies aim to track these children through adolescence to determine if early cognitive and behavioral difficulties persist or worsen over time.

Comparing New Findings With Previous Research

The relationship between prenatal cannabis exposure and childhood development has been investigated for decades. However, recent studies provide stronger evidence due to improved research techniques and larger, more diverse sample populations.

Increased THC Potency and Developmental Risks

One crucial factor setting recent studies apart is the increasing potency of cannabis products. THC concentrations in cannabis have risen significantly over the past few decades, with some modern strains containing three to four times the THC levels found in cannabis from the 1990s. Increased THC exposure may amplify the potential risks to fetal brain development, making today’s findings even more concerning than past research.

Medical and Health Authorities’ Warnings

Major health organizations strongly advise against cannabis use during pregnancy.

• The American Academy of Pediatrics (AAP) and the American College of Obstetricians and Gynecologists (ACOG) both recommend that pregnant individuals avoid cannabis due to its potential neurodevelopmental impact.
• The Centers for Disease Control and Prevention (CDC) cautions that THC can enter the fetal brain and may disrupt normal development, leading to cognitive and behavioral impairments.

These warnings highlight the need for increased education on the potential risks associated with prenatal cannabis use and encourage expecting parents to seek safer alternatives for managing pregnancy-related symptoms.

Challenges in Studying Prenatal Cannabis Effects

Despite growing evidence linking prenatal cannabis exposure to cognitive and behavioral challenges, certain limitations persist in research:

Addressing Misconceptions About Prenatal Cannabis Use

A common misconception is that because cannabis is plant-based, it must be harmless, especially compared to pharmaceutical medications. However, "natural" does not always mean "safe."