Do Pot and Pregnancy Mix?

The evidence concerning marijuana's effect on fetuses is mixed and incomplete.

Since 1985 cigarette packages sold in the United States have carried four rotating warnings from the surgeon general, including this one: "Smoking by Pregnant Women May Result in Fetal Injury, Premature Birth, and Low Birth Weight." Since 1989 the labels of alcoholic beverages have included this government-mandated warning: "According to the Surgeon General, women should not drink alcoholic beverages during pregnancy because of the risk of birth defects." Last week the American Medical Association (AMA) proposed a similar label for cannabis products:  "Marijuana use during pregnancy and breastfeeding poses potential harms."

The proposed warning represents a concession to political reality by the AMA, which opposes marijuana legalization but seems to recognize that pot prohibition is inexorably crumbling. The AMA's wording is notably milder than the warnings for tobacco and alcohol—appropriately so, since the evidence that cannabis consumption during pregnancy can harm the fetus is less clear than the evidence that smoking and heavy drinking can. In any case, providing information about marijuana's hazards is surely preferable to the punitive moralism of the war on drugs.

The latter approach still prevails in most of the country, as illustrated by what happened to Hollie Sanford and her baby girl, Nova. After Sanford gave birth at Cleveland's Fairview Hospital on September 26, Nova was snatched away from her because the newborn's first stool tested positive for a marijuana metabolite. Against the recommendation of county social workers (who are usually the villains in stories like this), Cuyahoga County Juvenile Court Magistrate Eleanore Hilow decided the drug test result by itself justified separating Nova from her parents. They were not reunited until November 9, after a judge overruled Hilow.

Sanford used cannabis tea to treat morning sickness and severe sciatic nerve pain while she was pregnant with Nova, as she had when she was pregnant with Nova's brother, Logan, who is now almost 2. Her research convinced her marijuana was a safer choice than the painkillers she had been prescribed, and she may be right about that. The Food and Drug Administration puts opioids such as hydrocodone and oxycodone in Category C, meaning "animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans," although "potential benefits may warrant use of the drug in pregnant women despite potential risks." The evidence concerning marijuana's effects on fetuses is likewise mixed and incomplete.

The National Institute on Drug Abuse, whose raison d'etre is highlighting the hazards of illegal intoxicants, says "research in rats suggests that exposure to even low concentrations of THC late in pregnancy could have profound and long-lasting consequences for both brain and behavior of offspring." It adds that "human studies have shown that some babies born to women who used marijuana during their pregnancies respond differently to visual stimuli, tremble more, and have a high-pitched cry, which could indicate problems with neurological development." NIDA also notes that "children prenatally exposed to marijuana are more likely to show gaps in problem-solving skills, memory, and the ability to remain attentive." But it admits that "more research is needed…to disentangle marijuana's specific effects from other environmental factors, including maternal nutrition, exposure to nurturing/neglect, and use of other substances by mothers."

That's a crucial concession. While animal studies can be carefully controlled to exclude alternative explanations for a given outcome, their results are not necessarily relevant to humans. Studies with human subjects, by contrast, are observational rather than experimental, since it would be unethical to randomly assign one group of pregnant women to use marijuana and another to abstain from it. So when a study finds, for example, that the children of women who consumed cannabis during pregnancy tend to be more impulsive as teenagers than the children of women who didn't, it is hard to say whether that's an effect of prenatal marijuana exposure or other factors associated with it.

The fact that studies do not consistently find such associations adds to the uncertainty. A widely cited 1994 study, for instance, used the Brazelton Neonatal Behavioral Assessment Scale to compare the babies of 24 Jamaican women who had used marijuana during pregnancy with the babies of 20 women who had not. At three days, there was no difference between the two groups. At one month, the children of the marijuana users actually had better scores, which the researchers attributed to "the cultural positioning and social and economic characteristics of mothers using marijuana that select for the use of marijuana but also promote neonatal development."

Paul Armentano, deputy director of the National Organization for the Reform of Marijuana Laws, notes that other studies with much larger samples in the U.K., Australia, and the Netherlands likewise have found no evidence of fetal harm from marijuana exposure once confounding variables such as smoking and mother's age were taken into account. After reviewing the evidence, Armentano concludes that "there is not a definitive answer" to the question of whether marijuana use is "safe for moms or not," although he adds that "it may be arguable that potential pre-natal and post-natal dangers posed by maternal pot use—particularly moderate use—are rather minimal, especially when compared to in utero exposure [to] alcohol and tobacco."

After doing her own research, Hollie Sanford concluded that the possible risks posed by marijuana were acceptable in light of its medicinal value. Patients and their doctors make that sort of judgment all the time, as reflected in the FDA's allowance that the "potential benefits" of a Category C medicine such as hydrocodone "may warrant use of the drug in pregnant women despite potential risks." In the case of marijuana, those benefits may include relief of otherwise unbearable pain (like Sanford experienced) or the severe, life-threatening nausea that afflicts some expectant mothers.

Hilow, the magistrate who ordered Nova's removal from her parents' custody, was not interested in weighing the risks and benefits of medical marijuana. All she knew was that marijuana is illegal, meaning that someone who consumes it is ipso facto an unfit parent.

In a previous case, the Cleveland Plain Dealer reports, Hilow thought it was obvious that a man caught with marijuana in his home should lose custody of his son. When the psychotherapist treating the boy disagreed, Hilow was so outraged that she sought to have the therapist replaced. An appeals court "found that the boy should live with the father and that the therapist should continue to treat him."

Despite that experience, Hilow's prejudice against cannabis consumers was strong enough to override the recommendations of county officials who said separating Nova from her parents was not in the child's best interest. "There is no need to remove this child from her parents in order to protect her," an assistant county prosecutor wrote in an October 23 motion. "At this time, removal would only serve to disrupt the bond the child would develop with her parents during this important period in her life…Rather than protecting the child, removal may be more harmful to her both in the present and in the future."

Hilow was unmoved by that argument. Fortunately, Sanford's cousin agreed to take care of Nova to keep her from being placed with strangers in a foster home, and Sanford was allowed to visit Nova at her cousin's house during the weeks when Hilow's order was in effect.

"It's outrageous," attorney Joseph Jacobs, who represents Sanford and her husband, Daniel, told The Plain Dealer. "The decision has no basis in law or science. There was no harm done to this child other than the removal from her mom and dad." Jacobs told WJW, the Fox station in Cleveland, that the hospital should not even have performed the drug test, since the baby was born "very healthy and alert," the Sanfords did not consent to testing, and they are not on public assistance or covered by Medicaid, programs that require drug screening.

No mother, regardless of where she gets her health coverage, should be branded unfit simply because she used marijuana (or any other illegal drug) during pregnancy. Since drinkers and smokers do not lose custody of their newborn babies because they failed to abstain during pregnancy, it is plainly illogical to treat cannabis consumers that way, especially when they have compelling medical reasons to use marijuana. Such disparate treatment has nothing to do with the hazards posed by such behavior; it is due entirely to the arbitrary distinctions drawn by our drug laws. The fact that Hilow's cruel order was overturned in a state where marijuana remains illegal for all uses suggests that her brand of pharmacological bigotry is losing its power.

This article originally appeared at Forbes.com.