COVID-19 Clinical Trials: Should Pregnant Women Be Included?

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Scientists and clinicians are working as fast as they can to come up with drug treatments and vaccines that will work against SARS-CoV-2, the coronavirus responsible for the COVID-19 pandemic. Unfortunately, pregnant and lactating people were not initially included in any of the clinical trials for coronavirus treatments and vaccinations. In this post, we’ll discuss why pregnant and breastfeeding women should be included in clinical trials, especially during a pandemic.

Why pregnant people have not been included in clinical research in the past

Historically, clinical researchers have not included pregnant or breastfeeding people in clinical trials because it was viewed as unethical. Clinical trials, especially phase I trials that focus on safety, carry a certain amount of risk. It is hard to justify bringing that risk to a pregnant person, whose body is already under different types of stress, and to a fetus, which undergoes many important developmental changes that could be perturbed by something in the environment like a drug or vaccine. Researchers who advocate not including women in clinical trials point to instances where fetuses were harmed by exposure to medication. Plus, women—let alone those who were pregnant or breastfeeding—weren’t even regularly included in clinical trials until the 1990s.

The case for including pregnant and breastfeeding people in clinical trials

There are plenty of drugs to be avoided during pregnancy or breastfeeding based on known issues they could cause for the developing or nursing baby. But there are even more drugs without enough information about use in pregnant or breastfeeding women. That’s especially true now, as new drugs and vaccines are being developed every day to help treat and prevent COVID-19. And while it doesn’t appear that pregnant or breastfeeding people are any more susceptible to the coronavirus, there are pregnant and breastfeeding people who have gotten the disease. Because they are not being included in clinical trials, those trials aren’t gaining any new information that could help pregnant and breastfeeding people who get COVID-19 in the future.

There is emphasis on the importance of including pregnant people in vaccine trials, as the benefits of vaccination are three-fold: for the mother, fetus, and newborn.

The example of remdesivir

Remdesivir is a drug that was originally developed to treat another virus—Ebola—but in the lab, it appears to be more effective against coronaviruses. According to maternal-fetal medicine and breastfeeding specialist, Alison Stuebe, who wrote a commentary published on May 18th in the journal Breastfeeding Medicine, remdesivir is available for compassionate use for pregnant women who have COVID-19, but people who are breastfeeding and also have COVID-19 are urged to stop breastfeeding while they take the drug, which could force people to choose between their own health and the benefits—including immune support—the baby could gain via breastfeeding.

Stuebe also explains in the commentary that here are ongoing clinical trials around the world to test whether remdesivir is effective against SARS-CoV-2, but breastfeeding and lactating people are not included in them. This means that there is not information about whether or not the drug makes it into milk—and if it does, in what quantities. Given what researchers know about remdesivir, Stuebe writes, it is unlikely that the drug could end up in a baby’s bloodstream in its active form. But without the clinical trials, researchers and care providers just don’t know.

Final thoughts

Clare Whitehead and Susan Walker, both obstetricians at the University of Melbourne in Australia recently authored a letter in The Lancet on this topic. They explain that if pregnant and lactating people continue to be excluded from clinical trials, they—and the care providers who treat them—will have fewer options for evidence-based care if they do get sick. While it’s possible that data will be collected about their exposure to drugs after the fact, this kind of data does not provide the same quality of information as randomized clinical trials. Whitehead and Walker also emphasize the importance of including pregnant people in vaccine trials, as the benefits of vaccination are three-fold: for the mother, fetus, and newborn.

Abby Olena
Dr. Abby Olena has a PhD in Biological Sciences from Vanderbilt University. She lives with her husband and children in North Carolina, where she writes about science and parenting, produces a conversational podcast, and teaches prenatal yoga.

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