Synthetic Marijuana Linked to Major Birth Defect

Deborah Brauser

August 17, 2012

August 17, 2012 — Today's strains of marijuana are up to 20 times more potent than strains popular in the 1970s and 1980s — and present a higher risk for adverse effects on fetal neurodevelopment, including anencephaly, new research shows.

Although a recent study estimated that the worldwide use of marijuana by pregnant women is as high as 20%, many of these women are unaware of the potential harm they are doing to their baby by exposing them to high levels of tetrahydrocannabinol (THC), noted the investigators in a release.

"The argument that this is a harmless drug is no longer valid due to the emergence of bioengineered crops, blends, and novel, medicinal marijuana strains," lead author Delphine Psychoyos, PhD, who was affiliated with the Center for Environmental and Genetic Medicine at Texas A&M Health Science Center in Houston at the time the study was conducted, told Medscape Medical News.

Dr. Delphine Psychoyos

She added that the synthetic cannabinoids AM694 and HU210 that are found in so-called Spice products are 500 to 600 times more potent than the THC found in "traditional" marijuana.

"The THC contained in high-potency marijuana and the potent THC analogues contained in Spice products...are potentially harmful to embryonic development as early as 2 weeks after conception. By the time a woman realizes she is pregnant and stops taking these substances, it may already be too late for her unborn child," said Dr. Psychoyos in the release.

The review was published online August 13 in Drug Testing and Analysis.

Anencephaly, ADHD, Depression, Aggression

According to the investigators, previous research has shown that in utero exposure to marijuana has been linked to anencephaly, a condition in which the forebrain fails to form, as well as with later development of attention-deficit/hyperactivity disorder, learning disabilities, memory impairment, depression, and aggression.

Other recent studies have suggested that the developing central nervous system (CNS) is particularly susceptible to the effects of THC.

"These exocannabinoids interfere with the function of an endocannabinoid (eCB) system, present in the developing CNS...and required for proliferation, migration, and differentiation of neurons," write the researchers.

Dr. Psychoyos reported that some medicinal marijuana blends, such as the so-called "Connie Chung" strain, contain up to 20 times more THC than marijuana commonly found 40 years ago.

"The problem is that many women who are pregnant or are planning to become pregnant are totally unaware of this [new] increased potency and the risks they pose," she said.

"Many Web sites on mothering and pregnancy, and those run by pro-marijuana advocacy groups, base their discussions on data collected prior to 1997, when no detrimental effects on pregnancy had been reported," added Dr. Psychoyos.

For this review, the investigators sought to analyze the potentially adverse effects of exocannabinoids and synthetic cannabinoids on early gestation and CNS development in human and animal models.

Teens, Young Adults Need to Know the Risks

Although there are currently no studies on effects on the eCB system during gestation weeks 2 to 4 in humans, studies examining chicks and mice at equivalent developmental stages have been conducted.

"An important point here is that an eCB system is indeed present in early neural development, and that this system is amenable to potential interference by exocannabinoids," write the researchers.

In addition, they reported the following findings:

  • Exposure to marijuana at 1 to 4 weeks of human gestation was linked to an increased risk for anencephaly;

  • Exposure to marijuana at 18 to 22 weeks of gestation was associated with abnormal neuronal circuitry in cognitive and emotional brain centers; and

  • Animal studies showed that in utero exposure to Spice products increased risk for anencephaly.

Dr. Psychoyos noted that further studies are needed on the effects of human gestational exposure to Spice products and to cannabinoid research chemicals.

She added that high-potency marijuana and Spice products are also dangerous for young users, who usually do not realize what they are dealing with.

"Clearly, additional awareness should be provided to teens and young adults in particular concerning the health deficits caused by marijuana, especially given the current debates on rescheduling, legalization, and decriminalization of marijuana based on its medical applications," write the investigators.

A "Real Wake-Up Call"

"It appears that there is some pretty good evidence, at least with animal studies, to suggest that these highly potent cannabinoids do have some effects on the development of neural tissue," Mark Hudak, MD, professor of pediatrics and division chief of neonatology at the University of Florida College of Medicine in Jacksonville, told Medscape Medical News.

Dr. Mark Hudak

However, he said that the article begs the question: are there now actual clinical data clearly telling what these effects are on the development of human babies?

"And the answer to that right now is 'no'," said Dr. Hudak, who was not involved with this research.

"Still, if you say there are no long-term harmful effects from this exposure, that doesn't translate to being able to say that exposure of fetuses to marijuana or these potent cannabinoids is also harmless."

He noted that a study published in Epidemiology in 2009 that examined data from the National Birth Defects Prevention Study showed an increased risk for anencephaly in fetuses exposed during the first month of gestation to maternal cannabis use.

"It wasn't a really big increase, but it was there. Also, some of the information on what the long-term effects are in neurodevelopment status has caused some concerns, such as a suggestion of an increase in tremors and impulsivity," said Dr. Hudak.

"There isn't a great deal of information on this topic, but it suggests that there may be some issues," he added.

Dr. Hudak said that clinicians who treat women of childbearing age should keep these findings in mind and should warn their patients — even if they are not currently considering pregnancy.

"This would be part of good preventive care for women. As a physician, you take a history of sexual activity, you talk about the risks of unprotected sex, and you talk about the things we know are risks to the fetus, including alcohol and now marijuana," he said.

"The process of developing a baby is very complex and occurs in different stages, with the paper saying that neural tissue occurs in the first 14 to 19 days. I think that's a real wake-up call. Knowledge is important. After that, it's their choice. But presenting this information in a nonjudgmental way is just part of a good preventive approach to medicine."

The study was supported by Ruth L. Kirchstein and the National Research Service Award in Neurosciences from the National Institute on Drug Abuse and by grants from the National Institutes of Health. The study authors and Dr. Hudak have disclosed no relevant financial relationships.

Drug Test Anal. Published online August 13, 2012. Abstract