Cannabis Use During Pregnancy Could Lead to Mental Health Issues In Newborns: Study

Researchers found hormone and gene disruptions in the placentas of women who used marijuana during pregnancy.

According to the findings of new research, a mother’s use of cannabis during pregnancy may increase the risk of her child developing mental health and behavioral issues, potentially leading lead to increased aggression and abnormal heart functionality.

In a study published last week in the medical journal Proceedings of the National Academy of Science, researchers from the Icahn School of Medicine at Mount Sinai in New York found that children born to women who used cannabis during pregnancy had elevated levels of stress, aggression and hyperactivity at a young age.

Researchers reviewed a subset of data from a National Institute of Mental Health (NIMH) funded study, called “The Stress in Pregnancy”, which began in 2009 to evaluate the extent to which an adverse environment in utero can alter fetal growth and development, with potential lifelong impacts on health and disease. Participants were evaluated during each trimester, and had a four-year follow up with their children. Data on 322 pairs of mothers and children were collected, of which 71 mothers reported using cannabis throughout various stages of their pregnancy.

According to the findings, samples of the placentas from those who used marijuana during pregnancy had reduced expression of several genes associated with immune system function that directly correlated to increased risks of anxiety, aggression, and hyperactivity in their offspring.

At the four-year follow up period, hair samples of children were collected for testing. Researchers found children that were exposed to cannabis during pregnancy had elevated levels of the stress hormone cortisol when compared to children not exposed during pregnancy.

Those exposed to cannabis during pregnancy were also found to have reduced heart rate variability, which is a unit of measure to determine how well one’s heart can speed up and slow down, and is typically an early warning sign of an increased risk of anxiety-related disorders, according to the study.

The researchers concluded use of marijuana during critical developmental stages of pregnancy may cause hormone and gene disruptions in the placenta, which could result in long term and irreversible health consequences for children.

Marijuana Use on the Rise

In the early 2000s, roughly 3% of pregnant women indicated that they used marijuana during pregnancy. Now, as marijuana has become legalized in many states and is widely available in other forms, such as edibles, more people are partaking in marijuana use. Roughly 7% of pregnant women report using cannabis now, with many believing it to help with nausea or morning sickness

However, a growing number of studies have surfaced over the last several years raising concerns about the side effects of marijuana use during pregnancy and the possible adverse health effects it may have on young children.

In June 2019, the Journal of the American Medical Association (JAMA) published a study by Canadian researchers finding use of cannabis during pregnancy doubles the risk of a premature birth when compared to women who do not use it during pregnancy.

The findings also indicate pregnancy marijuana risks may include having smaller than normal babies and having babies that require treatment in the neonatal intensive care unit (NICU). Infants born to marijuana users also had 5-minute Apgar scores less than 4.

In September 2020, peer-reviewed medical journal, JAMA Psychiatry, published a study by Washington University researchers which found women who use marijuana during pregnancy may face an increased risk that their baby suffers from attention problems, behavioral issues, higher incidence of depression and anxiety, and sleep disturbances. Exposed children were also found to have lower cognitive performance.