Although cannabis is legal in many states in the U.S. (for both medical and recreational use), that doesn’t mean it’s safe for developing babies in the womb.
In fact, a recent study published in JAMA Pediatrics found that children exposed to cannabis (e.g., marijuana) during pregnancy exhibited poorer executive functioning—such as difficulty with attention and problem-solving—as well as increased aggressive behavior at age 5 compared to their non-exposed peers.1
Is This Study Legit?
Like any study, the JAMA Pediatrics study has its strengths and limitations.
The Pros of the Study:
- Solid Study Design: The study was a cohort study, which is one of the more reliable types of observational studies. However, cohort studies are not as robust as randomized controlled trials (RCTs), which provide the highest level of evidence.
- Respected Source: The study was published in a highly regarded medical journal, JAMA Pediatrics.
- Objective Measures: Urine toxicology reports were used to the verify the cannabis exposure and neuropsychological tests were used to evaluate the kids in the study, adding an objective layer to the data collection process.
The Cons of the Study:
- The Percent of Kids Exposed to Cannabis Was Somewhat Small: The study looked at over 11,000 children, but only 655 of them were exposed to cannabis in the womb. While still a decent sample, it’s a relatively small percentage, making it harder to draw broad conclusions.
- No Info on How Much Cannabis Was Used: The study didn’t specify how much cannabis the pregnant women were consuming, making it hard to establish a dose-response relationship.
- A Portion of the Data Was Self-Reported: Although urine tests and neuropsychological tests were included, some of the data was self-reported, which can make it prone to bias.
What Does This Mean for Pregnant Individuals?
Even though the study had its limitations, it adds to the growing body of evidence that cannabis use during pregnancy may harm a baby’s development.
As cannabis becomes more widely available (and legal) in the U.S., health officials are increasingly concerned about its potential effects on children. These concerns range from fears about prenatal exposure to cannabis to what happens when kids accidentally ingest cannabis-infused gummies (which is more common than you might think).2
Before this study, both the American Academy of Pediatrics (the AAP) and the American College of Obstetricians and Gynecologists (ACOG) had already recommended avoiding cannabis during pregnancy and while breastfeeding.3
Why Do the AAP and ACOG Recommend Avoiding Cannabis?
One key reason is that THC, the psychoactive compound in cannabis, can cross the placenta. This means that THC can reach the developing fetus and enter the baby’s bloodstream, potentially affecting fetal brain development.
Additionally, THC can accumulate in breast milk and remain there for hours to days after use. Therefore, breastfeeding babies may be exposed to THC through nursing, as well.
The impact of cannabis on fetal and infant development remains an area of active research. While researchers can’t study the effects of cannabis directly on pregnant women (for ethical reasons), existing evidence supports the AAP and ACOG’s cautious stance.
This new study from JAMA Pediatrics provides additional support for their recommendations, emphasizing the potential for cognitive and behavioral challenges in children exposed to cannabis in the womb.
The Bottom Line
Cannabis may be legal in many states, but that doesn’t mean it’s safe during pregnancy.
If you use cannabis and you’re pregnant or you’re planning to become pregnant, let your OB/GYN or midwife know. And don’t worry—they’re required to be discreet and maintain your privacy under HIPAA laws. Also, remember there are many resources available to help, including counseling services, support groups, and treatment programs. You’re not alone—support is available if you need it.
