As the first doses of the COVID-19 vaccine are being administered to people across the United States, a leading physician group is calling for pregnant people to be included, too.
The American College of Obstetricians and Gynecologists (ACOG), a professional membership organization for OB-GYNs, issued a practice advisory Sunday to say that both pregnant and breastfeeding people who are in the priority groups for the vaccine should receive doses as well.
"ACOG recommends that COVID-19 vaccines should not be withheld from pregnant individuals who meet criteria for vaccination based on [Advisory Committee on Immunization Practices]-recommended priority groups," the statement read. "COVID-19 vaccines should be offered to lactating individuals similar to non-lactating individuals when they meet criteria for receipt of the vaccine based on prioritization groups outlined by the ACIP."
The first doses of the Pfizer-BioNTech coronavirus vaccine, the first available in the United States, are currently being administered to health care workers and nursing home staffers.
More than 75% of health care workers are women, and around 330,000 health care personnel are estimated to be pregnant or recently postpartum, according to a report released in October by the Centers for Disease Control and Prevention (CDC).
Pregnant people have not been actively included in the late-stage clinical trials for any COVID-19 vaccines, including the Pfizer-BioNTech and Moderna vaccines in the U.S.
"I wanted to be here, I was excited to be here. For myself, my family, my patients, for the community at large, for the world at large... We will concur this virus." Yves Duroseau, MD, @lenoxhill ED chairman after receiving the #CovidVaccine today #VaccinesWork pic.twitter.com/xlqtCOgvKe
— Michael J. Dowling (@MichaelJDowling) December 14, 2020
The U.S. Food and Drug Administration (FDA) authorized the Pfizer-BioNTech vaccine for emergency use last week. Just prior to the vaccine's authorization, the CDC noted that a person in a priority group "may choose to be vaccinated" during pregnancy and can make an informed decision by speaking with their health care provider to better understand the potential risks and benefits.
In its practice advisory, ACOG noted there is no "safety data specific to use in pregnancy" for the vaccine, adding, "Individuals considering a COVID-19 vaccine should have access to available information about the safety and efficacy of the vaccine, including information about data that are not available."
The organization also said pregnancy testing should not be a requirement for receiving the Pfizer-BioNTech vaccine and that a conversation with a clinician should also not be required prior to vaccination, "as this may cause unnecessary barriers to access." The CDC also does not recommend getting a pregnancy test prior to the vaccine.
ACOG noted its practice advisory on vaccines and pregnant people will "evolve" as more data is collected and more information is learned about the vaccine.
Neither Pfizer nor Moderna have publicly released a timeline yet for including pregnant people in clinical trials.
Pfizer began opening its clinical trial to children as young as 12 earlier this fall. Moderna said in a filing earlier this month that they plan to start recruiting children between 12 to 18 years old to participate in its clinical trial.
Both the Pfizer and Moderna vaccines use mRNA technology, which uses pieces of genetic material to coax the body into developing defenses against future infection. If approved, they would be the first mRNA vaccines, which are theoretically safer during pregnancy because they do not contain a live virus.
Not recruiting parents-to-be in clinical trials and medical research is nothing new, according to Dr. Ruth Faden, the founder of the Johns Hopkins Berman Institute of Bioethics and a bioethicist who studies the ethics of pregnancy and vaccines.
"For a very long time, pregnant women were not included in biomedical research evaluation efforts or clinical trials, both for concerns about fetal development and what would be the implications of giving a pregnant women an experimental drug or vaccine and also for legal liability worries from manufacturers and pharmaceutical companies," Faden told "GMA." "There’s a huge gap between what we know about the safety and effectiveness of a new drug or a new vaccine for the rest of the population and what we know about it specific to pregnancy."
In the case of the COVID-19 vaccines, health experts have only one of the three sources of evidence that are used to evaluate safety and efficacy during pregnancy: the data on non-pregnant people who were enrolled in the clinical trials, according to Faden.
From that, Faden said, health experts can try to glean what side effects may happen to people who are pregnant, but it is not an exact science.
However, it's considered typical -- and many argue ethically appropriate -- to study an unknown substance first in healthy adults and then progressively in broader and broader populations. Pregnant people and children are often tested later down the line because of concerns about potential long-term harm.
Meanwhile, while ongoing COVID-19 vaccine clinical studies don't include pregnant people directly, some of the volunteers who sign up may become pregnant during the trial, which will give researchers some insights about the vaccine's safety among this group.
Dr. Stephen Hahn, commissioner of the U.S. Food and Drug Administration (FDA), said earlier this month the agency does plan to look at that data.
"In the clinical trials, we did not require a pregnancy test for entry into the clinical trials, which means that when we look at the data, there are likely going to be women of childbearing age who have gotten pregnant," Hahn told ABC News chief medical correspondent Dr. Jennifer Ashton in an interview on ABC News' Instagram Live. "So we are likely to be able to see data. I can't prejudge those data, but it's one of the things we'll have to look at."
"Will that be enough data for us to have confidence and say pregnant women should be vaccinated? I think that's something that we'll have to take a look at," he added.
What should pregnant people do?
The question of whether an expecting parent should receive a COVID-19 vaccine will eventually come down to a number of factors, including everything from the trimester, risk factors for COVID-19, ability to remain socially distanced in their lifestyle and occupation, guidance from federal and state officials and recommendations from a person's own physicians, experts say.
Overall, people should feel comfortable that a COVID-19 vaccine is safe, but parents-to-be might need to wait a bit before receiving one, according to Dr. Rashmi Rao, a maternal-fetal medicine specialist at UCLA Medical Center in Los Angeles.
"The message right now is that once it gets cleared from the FDA and vaccinations become available, if it’s safe to do so for the public, then I would recommend that you get your vaccination when you’re eligible," she said. "However, if you’re pregnant, you will likely have to wait until you’re no longer pregnant or until we gather more data regarding safety and pregnancy."
Similar to the flu vaccine, which was not tested on pregnant people in clinical trials, health experts will need to rely on continuously incoming data to make decisions around how safe the COVID-19 vaccines are during pregnancy. Officials are doing the same for the general population, considering the speed at which the COVID-19 vaccines were developed, according to Faden, who noted that people who are pregnant should not be "unnecessarily alarmed."
"Vaccines are coming, and they're coming before we have all of the information that we would like to have to make recommendations for pregnant people," she said. "But this is the context in which decisions are being made and recommendations are being made for the general population, without all of the evidence we would like to have, which is why the studies will continue."
The Society for Maternal-Fetal Medicine (SMFM) released a statement earlier this month encouraging expecting parents to "engage in shared decision-making" about the vaccine with their doctors.
"In general, SMFM strongly recommends that pregnant women have access to COVID-19 vaccines in all phases of future vaccine campaigns, and that she and her health care professional engage in shared decision-making regarding her receipt of the vaccine. ... mRNA vaccines, which are likely to be the first vaccines available, do not contain a live virus but rather induce humoral and cellular immune response through the use of viral mRNA," the society said in its statement. "Health care professionals should also counsel their patients that the theoretical risk of fetal harm from mRNA vaccines is very low."
SMFM’s Health Policy and Advocacy Committee strongly calls for the inclusion of pregnant and lactating individuals in vaccine trials in a recently published op-ed for Vaccine. #VaccinesWork #SafeMedsforMoms @caraheuser https://t.co/ytbZLNAQAq pic.twitter.com/qUmFsG0fI3
— SMFM (@MySMFM) December 10, 2020
Even now, nearly one year into the coronavirus pandemic in the U.S., many questions remain about how pregnant people are impacted by COVID-19.
The CDC has shared data showing that people who are pregnant have a significantly greater risk for severe illness from COVID-19 when compared to nonpregnant people, but they are not at a greater risk for death.
"What I tell my patients is the one thing I know for sure is that pregnant women can get COVID," Rao said. "We’re not seeing huge rates of any adverse fetal outcomes yet, but, again, that’s still to be determined, because we have a long way to go with collecting information."
Rao said everyone, including pregnant people, needs to remain on guard when it comes to COVID-19 by continuing to follow safety protocols, including face mask wearing, social distancing and hand washing.
ABC News' Sony Salzman and Eric Strauss contributed to this report.