Making Sense of Bioethics: Evaluating medical marijuana use during pregnancy

In 2020, Amanda Aguilar was arrested after using marijuana while pregnant. After her son tested positive for marijuana at birth, she was charged with child neglect. 

She fought the charge, arguing that she had turned to medical marijuana to treat severe morning sickness during her pregnancy, having received a doctor-approved state license for its use in Oklahoma where she lived. 

Such “doctor-approved” licenses, it should be noted, are often generalized permits for unregulated personal use, rather than a medical professional’s prescribing, tracking and monitoring a patient at a tailored dose for a particular medical situation.

During the court proceedings, one of the judges stated that although Aguilar had a medical permit to use marijuana, her baby did not, so a mother exposing her baby to marijuana, he concluded, should be considered an illegal act. 

In 2024, however, the Oklahoma Court of Criminal Appeals ruled that current Oklahoma law, as written, would not allow women with state medical cards who use marijuana during pregnancy to be prosecuted for child neglect. The Court, in commenting on the case, nevertheless urged the Legislature to consider changing and updating the law so that women in these situations could, in fact, be criminally charged for child neglect.

Aguilar’s case shares some parallels with the consumption of alcohol during pregnancy, a practice strongly discouraged by medical professionals. The Centers for Disease Control (CDC) notes, “The baby's brain is developing throughout pregnancy and can be affected by exposure to alcohol at any time.” Similarly, the CDC emphasizes, “Alcohol use during pregnancy can cause a range of lifelong behavioral, intellectual and physical disabilities known as fetal alcohol spectrum disorders.” 

By similar reasoning, then, if it were known that exposure to marijuana in utero would likely result in developmental delays, behavioral problems or other health issues for the child, women should avoid marijuana during pregnancy, and medical permits to use marijuana should be limited or restricted under such circumstances.

The American College of Obstetricians and Gynecologists, The American Academy of Pediatrics and the CDC all recommend against marijuana use during pregnancy. The main psychoactive component of marijuana, known as delta-9-tetrahydrocannabinol or THC, has been shown to cross the placenta and can be detected in breast milk. 

In recent years in the United States, cannabis use by pregnant women has been rising notably, even as alcohol and tobacco use during pregnancy have been declining over the same period. The difference may reflect the success of cannabis legalization campaigns, which have increased the availability of marijuana and decreased perceived risks of use.

The body of research literature on cannabis use during pregnancy is not as extensive as it is for alcohol, and additional studies will be required to verify some of the negative effects reported for children born following in utero exposure to marijuana.

Nevertheless, a growing accumulation of research data is raising significant concerns and pointing toward a number of potential adverse outcomes from prenatal cannabis exposure. These include stillbirth, fetal growth restriction, preterm delivery, increased neonatal intensive care unit admissions, small-for-gestational-age infants and socio-behavioral and cognitive impairment. 

Especially during periods of critical neural growth and expansion in the fetal and infant brain, cannabis use during pregnancy and lactation raises the prospect of adversely affecting not only neurodevelopment, but also subsequent neuropsychiatric, behavioral and executive functioning of the child.

Given these significant concerns surrounding in utero cannabis exposure and its effects on children, following the advice of various professional medical associations to avoid cannabis during pregnancy makes good sense. 

If we carefully weigh the potentially addictive nature of medical marijuana for the mother, the risks to the baby from in utero cannabis exposure, the recommendations of professional medical societies and the availability of alternative approaches to dealing with morning sickness, the arguments for encouraging pregnant women to obtain licenses for medical marijuana to treat morning sickness do not seem compelling. 

Moreover, some individuals who use marijuana to treat nausea and vomiting, especially over a longer period, may experience a phenomenon called cannabinoid hyperemesis syndrome, in which the cannabis, rather than helping with morning sickness, actually exacerbates the situation by itself inducing bouts of vomiting and nausea. 

Even in severe cases of morning sickness where fluid loss through vomiting occurs to the point that a mother may end up losing five percent or more of her pre-pregnancy body weight, various effective treatments exist that do not rely on cannabis, and these are likely to be recommended by health care professionals. Several pharmaceuticals with good safety profiles can be used during pregnancy, as well as direct rehydration interventions to help with acute dehydration symptoms.

Every pregnancy involves at least two people, each of whom deserves care and respect. While it may sometimes be necessary to subject a mother to a needed medical treatment while tolerating a second and unintended effect that results in harm to her growing baby, turning to medical marijuana in an attempt to address morning sickness appears to be neither a necessary nor a prudent course of action.

Rev. Tadeusz Pacholczyk, Ph.D. earned his doctorate in neuroscience from Yale and did post-doctoral work at Harvard. He is a priest of the diocese of Fall River, MA, and serves as Senior Ethicist at The National Catholic Bioethics Center in Philadelphia. See ncbcenter.org and fathertad.com.