Dr. Jacqueline Parchem, a maternal-fetal medicine physician at UTHealth in Houston, considers herself a private person. Even still, she logged on to Twitter on Dec. 22 and began drafting a series of posts.
“Pregnant and unsure about the #COVID19 vaccine?” she wrote in a tweet that has now been liked more than 3,000 times. “You’re not alone. Got vaccinated today at 31 weeks [pregnant] and feel very fortunate. But it’s complicated.”
Over the course of nine tweets, Parchem broke down the thinking that went into her difficult decision to get vaccinated during pregnancy. Ultimately, she wrote, she decided her substantial risk of being exposed to COVID-19 while caring for patients outweighed any hypothetical risks associated with the vaccine—but the choice wasn’t easy.
There are virtually no data on how COVID-19 vaccines affect pregnant people and their fetuses, since vaccine makers—like many companies testing a new drug—enrolled only non-pregnant adults in their clinical trials. Plus, the two vaccines authorized so far in the U.S., those made by Moderna and Pfizer-BioNTech, are the first widely available shots to use mRNA technology, so there is little frame of reference as to how they might affect pregnant people. Moderna reportedly found no safety concerns after testing its shot in rats prior to or during pregnancy, but animal data only reveal so much.
While the mRNA technology used in Pfizer-BioNTech and Moderna’s shots hasn’t been tested on pregnant people, the U.S. Centers for Disease Control and Prevention (CDC) says “they are unlikely to pose a significant risk for people who are pregnant.” The vaccines do not contain live virus, which means they cannot infect the recipient with COVID-19, and they do not enter the part of the cell that holds DNA.
Still, without strong data, most U.S. health groups have essentially left the decision about whether to get vaccinated while pregnant—or while breastfeeding or trying to get pregnant—up to individuals. The CDC, the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine (of which Parchem is a member) say pregnant people should not be excluded from vaccination if they are otherwise eligible to get their shots, but they do not explicitly make a recommendation one way or the other.
In the U.K., however, health authorities have specifically stated that “those who are pregnant should not routinely have this vaccine,” though people at particularly high risk of COVID-19 exposure may choose to get it.
That pregnant people in the U.S. haven’t been excluded from vaccination is “great, but it doesn’t answer the question, ‘Should I get the vaccine?’” Parchem says.
Experts saw this dilemma coming. Even though millions of people in the U.S. alone give birth each year, pregnant people are frequently excluded from drug trials, in part due to understandable concerns about exposing unborn babies to potentially harmful substances. The legacies of drugs that were proven to be dangerous for pregnant people and their fetuses—including the anti-nausea medication thalidomide and the synthetic hormone diethylstilbestrol—after approval still loom large.
Pregnant people have historically been considered a “vulnerable” population—a designation also applied to groups, such as children and the incarcerated, who may be coerced into participating in research. OB/GYN and author Dr. Jen Gunter says that label was never appropriate for pregnant people, who are “more medically complex, for sure,” but are perfectly capable of deciding whether or not to enroll in a study.
The medical community is increasingly moving away from using the “vulnerable” label for pregnant people, but pharmaceutical companies must still take certain precautions when designing study protocols that include expectant mothers. Many simply choose not to—especially in situations, like developing COVID-19 vaccines, where speed is crucial. One study found that, out of 468 drugs approved by the U.S. Food and Drug Administration from 1980 to 2000, more than 90% came with no conclusive information about their risk of birth defects.
As a maternal-fetal medicine specialist, helping pregnant people navigate this dearth of research was part of Parchem’s job even before the pandemic. Taking drugs often presents a moral quandary for pregnant people, she says, since medications are rarely tested for use among that population.
“Naturally, people tend to center on the fetal risk,” Parchem says. But she says it’s also important to consider “the consequence of not getting this treatment” for the mother. In the case of COVID-19, that could include severe illness or death. Pregnant people who get COVID-19 are at increased risk of requiring intensive care, studies show, and they may also be at risk of complications including preterm birth.
Faced with that calculus, many other pregnant health care workers have chosen to get vaccinated. Dr. Leslie Kim, a facial plastic surgeon at the Ohio State University Wexner Medical Center, in early January posted on Twitter and Instagram about her decision to get vaccinated at 32 weeks pregnant.
After speaking with her own doctor, Kim, who regularly performs procedures on or near patients’ airways, decided her risk of exposure to COVID-19 was high enough to justify getting vaccinated.
Kim also felt a responsibility to add, in however small a way, to the public’s understanding of vaccination during pregnancy. “For pregnant people to be included in studies, they do have to volunteer,” Kim says. “All of us who are stepping forward…[are] contributing to the science of this vaccine.” While formal studies on COVID-19 vaccines and pregnancy have not yet been completed, Kim says she hopes others in her position are “diligently reporting side effects or anything we experience so we can help future people in our shoes.”
For Dr. Denise Cardenal, an OB/GYN affiliated with OB Hospitalist Group in St. Lucie, Fla., the desire to protect her family and community from COVID-19 provided motivation not only to get vaccinated at 31 weeks pregnant, but also to post about the decision on Facebook. “I’m not one to share anything about what I do as a physician on Facebook,” she says. But “I saw this as such an important opportunity to set an example.”
Already, she says, she’s heard from people who have decided to get vaccinated because she did.
Still, Cardenal emphasizes that the decision is a personal one. Someone who can stay home throughout her pregnancy may want to wait to get vaccinated until after she gives birth, whereas someone with a higher exposure risk may not. Each individual should talk to their doctor and read up on health groups’ guidance before making a choice, she says.
“People should question the data, the science, what is out there. You have to inform yourself,” Cardenal says. Hearing from health care workers who have chosen to get vaccinated can be part of that.
Until there are published clinical trial results, the best information about COVID-19 vaccines and pregnancy may indeed come from people choosing to share their private decisions publicly. “We don’t want to make any decisions by a [sample size] of one,” Gunter says, “but people stepping up is really an amazing service.”