Story URL: http://news.medill.northwestern.edu/chicago/news.aspx?id=227373
Story Retrieval Date: 8/1/2014 6:51:43 AM CST

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Joseph M. DiTomaso, University of California - Davis, Bugwood.org

A new study suggests that cannabis use among pregnant women can impair fetal brain development.


Pot during pregnancy bad for baby's brain, scientists report

by Natalie Pacini
Jan 30, 2014


Marijuana use during pregnancy inhibits fetal brain development and can have long-lasting effects on cognitive ability, according to a new study.

Researchers reported in the EMBO Journal that THC, the active ingredient in marijuana, affects a specific protein essential for the proper growth of neurons, the brain’s nerve cells.

The study, performed on mice and the brain tissue of human fetuses, found that those subjects exposed to marijuana in utero had significantly lower levels of the protein Superior Cervical Ganglion 10. Fetuses exposed to cannabis had about 40-50 percent less of this protein in their cerebral tissue than those not exposed to cannabis, according to researcher and neuroscientist Yasmin Hurd of Mount Sinai Hospital in New York.

Superior Cervical Ganglion 10, or SCG10, is the protein found in growing cells that defines how they will take their final shape, said researcher Tibor Harkany. Harkany, a neuroscientist, works for the Karolinska Institutet in Stockholm and the Medical University of Vienna.

The study, one of the first to look at molecular rather than behavioral effects of THC on fetuses, suggests that, “prenatal exposure to marijuana alters the wiring of the fetal brain, and this destabilizes the neural network which is linked to cognitive function,” Hurd said.

Such decreased cognitive function could inhibit basic skills such as organizing, planning, memory and decision-making later in life, she explained.

Harkany advised pregnant women to abstain from marijuana use during pregnancy. The study suggested that “cannabis [use] at a certain period of life may be detrimental and . . . certainly can change the fetal brain so that long-lasting changes may occur,” he said.

Dale Gieringer, director of California NORML (National Organization for Reform of Marijuana Laws) in San Francisco, contended that, because the findings are “removed from any real world clinical effects,” further research is necessary to determine the impact of THC on fetal brain formation.

Furthermore, marijuana use may have some benefits during pregnancy, he said.

Some of the oldest direct physical evidence of cannabis as medicine involves pregnant women, Gieringer explained. Its discovery in an ancient Near Eastern tomb alongside a young woman who died during childbirth suggested that it was perhaps used to ease labor pains ages ago.

He also suggested that marijuana may help ease morning sickness.

Medical marijuana is legal in 21 states and the District of Columbia, though the federal government still categorizes marijuana as an illegal drug having no medical use and posing a high risk for abuse among users.

On Jan. 1, medical marijuana became legal in Illinois, though official regulations are not likely to be set until April. It is unknown whether doctors will be allowed to prescribe marijuana to pregnant women, according to a spokeswoman for IllinoisMarijuanaClinics.com.