Health In Focus
  • Marijuana used by pregnant women to treat morning sickness can harm the baby’s brain
  • It results in behavioral, memory, and learning problems after birth
  • It is caused by damage to the nerve connections in the brain areas responsible for learning and memory

Marijuana used by pregnant women for treating morning sickness could be harmful to the developing brain of babies, suggests new research from Auburn University, USA.

The study was led by Prof. Vishnu Suppiramaniam, PhD, who is the Acting Associate Dean for Research and Graduate Programs at the Harrison School of Pharmacy, Auburn University, Alabama, USA. The research, carried out in pregnant rats, revealed how marijuana affects the developing brain of the fetus.
Marijuana Used to Treat Morning Sickness Harmful for Baby’s Brain

The study findings are being presented by Dr. Priyanka Das Pinky, MBBS, who is a PhD candidate in Suppiramaniam's lab at the American Society for Pharmacology and Experimental Therapeutics Annual Meeting during the 2019 Experimental Biology Meeting in Orlando, Florida, USA.

Salient Features of the Study

  • The study was carried out in pregnant female rats
  • Cannabinoids (active compounds in cannabis or marijuana) that activated the same proteins as cannabis (marijuana) were administered to the pregnant rats
  • The dose of cannabinoids was equivalent to a moderate to high dose of marijuana in humans
  • The synapses (connections between nerves) in the hippocampus (brain center for learning and memory) were damaged in baby rats exposed to cannabinoids
  • The underlying cause was a reduction in neural cell adhesion molecules (NCAM) that maintain proper neural connections at the synapses

Implications of the Study

Development of drugs that could elevate the levels of NCAM would help to counteract the harmful effects of marijuana on the developing fetal brain. However, further research is required to establish whether these animal model studies would be translatable to humans.

"The findings from this study will serve as an excellent premise for future interventions to restore memory in children exposed to cannabis during pregnancy, and for the first time, identify a specific mechanism by which learning and memory impairment occurs and how this impairment can be ameliorated," says Pinky.

Marijuana & its Harmful Effects

Marijuana, also known as cannabis among many other names, is a greenish colored mixture of dried flowers of the cannabis plant Cannabis sativa. It is a psychotropic drug that is primarily used for recreational and medical purposes. The active components of marijuana are cannabinoids.

The use of marijuana has skyrocketed after being legalized for medical and recreational purposes by several states in the US. For example, a previous study reported that marijuana use among pregnant women increased by a staggering 62 percent between 2002 and 2014. This mirrors the rise in marijuana use among the general population in the US within the same timeframe.

Previous studies have established that children born to mothers who used marijuana during pregnancy, developed behavioral problems, as well as learning and memory difficulties. The new study not only buttressed the previous findings, but also elucidated how the cannabinoids affect the nerve connections in the hippocampus. Establishing the mechanism of action of marijuana on these nerve connections in the brain could lead to the development of interventions to reduce the injury.

Future Plans

The research team plans to carry out further studies to dissect out the mechanism by which NCAM or its active form modulates cellular effects, so that target-specific drugs can be developed to ameliorate the cognitive defects.

Concluding Remarks

"Based on our research and the previous existing findings in the field, it can be said that using marijuana during pregnancy would not be a wise choice," says Pinky. "However, it is also notable that the observed effect in the offspring can vary according to their age and according to the trimester during which they were exposed to the drug as well as dose and route of administration of the drug."

Reference :

  1. Mechanism of Prenatal Cannabinoid Exposure Mediated Memory Loss in Adolescent Offspring: Opportunities for Identifying Therapeutic Target - (

Source: Medindia

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