Not only has the use of marijuana increased drastically in the last few decades, it is also being used at a younger age. And now even pregnant women are taking the drug at an increasing rate.

One survey found that among pregnant women between the ages of 14 to 44, 5.9 percent use illicit drugs. That includes 18 percent among pregnant girls ages 15 to 17. Another recent survey in the U.S. and Europe found that 10 percent of pregnant women are using marijuana.

This reflects an incredible disregard for the health of these babies. A number of studies have looked at the neurodevelopmental effects of marijuana exposure on babies during pregnancy. We know that cannabinoid receptors play a major role in brain development, especially in the architecture of various intricate brain structures such as synaptic development.

We also know that overstimulation of these receptors during critical periods of brain development can result in neurons that function abnormally. These receptors become active very early in human brain development, somewhere around week 19 after conception, and they are much more active in the fetal brain than the adult brain.

Stimulation of cannabinoid receptors during brain development affects several neurotransmitters, including catecholamines, glutamate, serotonin, opioids, and dopamine. This can have profound effects not only on brain development, but especially brain function later in a person’s life.

Marijuana has been shown to suppress these critical receptors. That means the presence of the drug would interfere with developmental molding of the brain’s microscopic structures.

For example, an important effect that occurs in babies exposed to marijuana in utero is that they are hyperactive and impulsive later in life. This impulsive behavior can increase risk-taking, violence, and even suicide. It has also been shown that prenatal exposure to marijuana during the first and third trimester can significantly predict anxiety and depression in 10-year-old children.