Is It Safe to Smoke Weed While Pregnant? Separating Science from Hysteria
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Is It Safe to Smoke Weed While Pregnant? Separating Science from Hysteria

The deficiency of scientific evidence continues to stop mothers from using the drug out of fear of harming their baby or being accused of child abuse.

Shaleen Title lost 30 pounds during the first trimester of her pregnancy due to a crippling case of hyperemesis gravidarum, a condition characterized by severe nausea and vomiting that can lead to dehydration and nutritional deficiencies.

Her doctor at the time suggested a triple-daily dose of Zofran, a drug used to help patients undergoing chemotherapy.

Shaleen, a Massachusetts lawyer and cannabis reform advocate, knew that medical marijuana is an effective treatment for nausea in cancer patients.


She also knew that although the medical use of the drug is legal in her home state, the risk of her using it for her nausea was too great: Her child could be taken away from her if she or the baby tested positive for marijuana exposure at birth.

But Shaleen didn't want to take Zofran, which was being prescribed off-label to pregnant women. Instead, she quit her job and spent months bedridden and vomiting.

Today, GlaxoSmithKline, the manufacturer of Zofran, is mired in a class action lawsuit due to recommending the drug for use during pregnancy without FDA approval. It has been shown to contribute to various birth defects such as cleft palate, clubfoot, craniosynostosis, and holes in the newborn's heart.

The first medical trial dedicated to marijuana use during pregnancy is happening in Colorado

Dr. Torri Metz, a high-risk obstetrician and Assistant Professor at the CU School of Medicine, is conducting a landmark study that will hopefully set a standard for understanding the effects of prenatal marijuana use.

Metz wants to look at the association between marijuana use and fetal growth restriction, hypertension in pregnant mothers, stillbirth, spontaneous preterm birth, and more.

"If you look at the literature now, you find very mixed results," she said in a statement. "About half [of the studies] say there is an association between marijuana use and adverse outcomes; about half say there is no association."


The trial will include 100 randomly selected women at UCH and Denver Health who Metz will approach within two days of delivery. In order to encourage honesty, the women will record their answers through a computer, rather than face-to-face, and they will receive certificates of confidentiality.

The study will then use a six-inch piece of the infant's umbilical cord—more accurate than the traditionally measured urine or meconium—to test for evidence of marijuana exposure.

"We don't really care about whether or not kids are living in poverty, but add a layer of marijuana on to it and everyone goes berserk."

Using marijuana during pregnancy is not illegal in states where it is legal for recreational or medical reasons, but the deficiency of scientific evidence continues to stop mothers from using the drug out of fear of harming their baby or being accused of child abuse.

Dr. Metz's is the best hope for getting definitive answers for women who want to know if it's safe to use marijuana while pregnant.

Tough to test

"Marijuana is still tricky to test," said Heather Thompson, a molecular biologist with Elephant Circle, a Colorado group that provides support to families around a variety of pregnancy and parenting issues.

Marijuana usage must be self-reported, and its effects typically cannot be isolated from other substances such as alcohol, tobacco, or other drugs, prescription or not.

Federal regulations also make it difficult to test the effects in a controlled scientific trial. Cannabis was listed as a Schedule I substance in the US in 1970, meaning it has "no currently accepted medical use" and federal funding for research on the drug is nonexistent.


For perspective, cocaine is a Schedule II substance, meaning that public funds are more easily allocated to studying positive and negative effects of the drug.

It was only last year that the Obama administration significantly cut down on the roadblocks surrounding marijuana research. On the state level, Colorado and California have the only approved public funding for medical cannabis research.

Existing research points to some possible mild detrimental effects, but is inconclusive

Three major longitudinal studies, which took place in Ottawa, Rotterdam, and Pittsburgh between 1978 and 2001, followed the families of mothers who used "common illicit" substances prenatally and afterwards for 20 years or more.

None of these studies aimed to look at solely the effects of marijuana, but rather marijuana and tobacco, marijuana and alcohol, and a wide range of substances, respectively.

In the short term, the only reported effects concerned neurobehavior, such as tremors or increased startling, symptoms that are indistinguishable from those caused by nicotine usage—which was not controlled in any of the studies.

Long-term conclusions showed possible negative impacts on the infant's behavior and cognition, but again, there was no way to tell whether these impacts were from marijuana or other factors known empirically to have similar effects, such as poverty, low socioeconomic status, and use of nicotine or alcohol.


The findings, despite being unconfirmed, created an impression that marijuana harms newborns. This reasoning has been used repeatedly to prosecute cannabis-using women for child abuse.

Even in legal states, prenatal marijuana use is treated the same as alcohol and tobacco and advised against by public health agencies and doctors.

Instances of manipulating the outcomes of prenatal drug studies isn't a new phenomenon. In the late 80s, the "crack baby" epidemic was a runaway media sensation that took information from a poorly-executed study and turned into a racist, classist war on women.

The effects of cocaine usage could not be isolated from the effects of poverty, which is almost always concurrent with poor levels of nutrition, stimulation, and community support. Over 200 mothers from poor communities in 30 states were charged with child abuse, and many infants were removed from homes.

"To characterize an infant born to a woman who used marijuana during pregnancy as being 'physically abused' and/or 'neglected' is contrary to all scientific evidence."

The reaction has been similar with marijuana. In 2011, a woman in Alabama was arrested for "chemical endangerment of a child" after testing positive for THC, the principal psychoactive metabolite present in cannabis, after birth. She denied using cannabis during her pregnancy. More recently, another mother in Ohio had her baby taken away by child services because she chose to drink cannabis tea instead of using prescription painkillers to ease her post-labor pains.


"We don't really care about whether or not kids are living in poverty, but add a layer of marijuana on to it and everyone goes berserk," said Thompson.

At least one study showed marijuana use is safe for pregnant mothers

This zero-tolerance policy toward pregnancy and marijuana is not scientifically supported.

"It is important to emphasize that to characterize an infant born to a woman who used marijuana during pregnancy as being 'physically abused' and/or 'neglected' is contrary to all scientific evidence," said Dr. Peter A. Fried, principal investigator of the Ottawa study, one of the few North American studies to look at the issue.

Furthermore, a 1994 study done by Dr. Melanie Dreher in Jamaica, where "ganja" is widely accepted both medically and culturally, found little difference in cannabis-exposed babies—if anything, they seemed to do better.

"The neonates of heavy-marijuana-using mothers had better scores on autonomic stability, quality of alertness, irritability, and self-regulation and were judged to be more rewarding for caregivers," the study said.

Michael Backes, author of Cannabis Pharmacy: The Practical Guide to Medical Marijuana says that our understanding of the endocannabinoid system is so complex that he cautions prenatal use simply due to our lack of scientific understanding of it—but he noted that prohibition has prevented what could potentially be a helpful medication for pregnant mothers.


Finally, we'll have some real data

With legalization on the horizon for more and more states, this is just the beginning of a crucial reproductive rights issue.

Recently, New York City ruled that bars and restaurants cannot refuse alcohol to pregnant women (a substance that, when prenatally abused, has documented detrimental effects), saying that "using safety as a pretext for discrimination or as a way to reinforce traditional gender norms or stereotypes is unlawful." Perhaps this type of thinking will spread to include the use of cannabis during pregnancy, whether it is prescribed or not.

Metz and her colleagues are developing the questionnaire pregnant mothers participating in the study; Elephant Circle is creating pamphlets and other documentation for dispensaries around Colorado to inform women of the current research and their rights.

In the meantime, advocates are working on rescheduling cannabis so more trials like Dr. Metz's will be able to be publically funded throughout the country.