The Studies Have Spoken: Covid Vaccines Are Safe During Pregnancy
An immunologist has compiled a list of 36 international studies — including more than 350,000 pregnant people — to put your fears to rest.
It’s not every day that a doctor is faced with the same decision as her patients: should I get vaccinated against Covid-19 in my first trimester? For Dr. Robyn Garcia, M.D., a maternal-fetal medicine physician at UTHealth Houston, who was six weeks into her pregnancy in October 2022, the answer was a no-brainer. “Every day, we all make choices that weigh risks and benefits of these choices — the Covid vaccination is no different,” says Garcia. And this is exactly what a new summary of 36 peer reviewed studies from eight countries, including the U.S., Canada, and the U.K., looking at 364,068 people vaccinated in pregnancy, has confirmed.
Dr. Victoria Male, Ph.D., an immunologist and lecturer in reproductive immunology at Imperial College London, began compiling this summary list at the end of 2021, because she was fielding so many questions about safety when Covid vaccines first rolled out. “By the end of 2021 there were enough studies that it made sense to put them all in a table, and since then I've just been adding new ones as they come out,” explains Male.
Male’s current list of 36 studies follows on from a 2022 review of 16 studies she published in Nature Reviews Immunology. Her updated list consolidates newer findings on the impact of Covid-19 vaccinations on and during pregnancy. “[These] studies focus on the safety of Covid vaccines in pregnancy and show that getting vaccinated doesn’t increase the risk of pregnancy problems,” says Male. Among other things, the list of studies confirms Covid vaccination during pregnancy does not increase the risk of preterm birth, neonatal death, miscarriage, or congenital abnormalities.
Male stresses that the Covid vaccines are no longer “new,” so there’s no reason to be anxious on that front.
Pregnant people are, however, at an increased risk for severe illness from Covid-19 and, per the Center for Disease Control and Prevention (CDC), those infected with the disease face an increased risk of preterm birth, stillbirths, and death — and “might be at increased risk for other pregnancy complications.”
Male’s list of studies confirms that vaccination during pregnancy reduces the chance you will catch Covid, however, in the event that you do, she explains that it also reduces your risk of hospitalization, Covid stillbirth, and death.
For example, a 2022 study published in the American Journal of Obstetrics and Gynecology confirmed that Covid-19 vaccination in pregnancy reduces the risk of stillbirth. The same study, which analyzed births from 32,536 women (53.4% vaccinated and 47.6% unvaccinated) found that vaccinations were linked to reduced preterm births, with babies born to vaccinated mothers having lower rates of admission to the neonatal intensive care unit. Of the 32,326 women in the study, a little over 1,000 became infected with Covid during their pregnancy — of this group, there was a “significant reduction” in preterm birth for those who had been vaccinated during their pregnancy.
Meanwhile, though current guidelines from the CDC recommend that all pregnant women be vaccinated against Covid-19, with the American College of Obstetricians and Gynecologists (ACOG) advising all people who are planning on becoming pregnant or are pregnant, postpartum, or breastfeeding to get fully vaccinated against Covid-19, a 2022 study confirmed that pregnant people less frequently receive the Covid-19 vaccination than their non-pregnant counterparts.
“I, amongst others that support maternal and fetal health, believe that the benefits of receiving a Covid-19 vaccine outweigh any potential risks of vaccination during pregnancy,” says Garcia, who is expecting her baby this summer.
Remember that OB-GYNs have dedicated their careers to treating women and their unborn babies and would never recommend a treatment that is not safe
Male clarifies that the risks and side effects of Covid vaccinations for pregnant people are “most commonly the same as those for anyone else receiving the vaccine”— namely, she says, “a sore arm and a general feeling of fatigue or body aches.” Between five and 50% of people may experience a fever, which, she adds, can be safely treated with acetaminophen. “The one serious side effect associated with mRNA COVID vaccination is myocarditis,” she notes. “This is rare, mostly affects males in their late teens to early twenties, and there have been no reported cases in pregnancy, but it is a theoretical possibility.” (The CDC advises vaccinated people with chest pain, a fast-beating heart, and shortness of breath to contact their medical care provider, especially if these symptoms present themselves one week within your Covid vaccination.)
As for those who are concerned that the vaccine is “too new” to consider taking while pregnant? Male stresses that the Covid vaccines are no longer “new,” so there’s no reason to be anxious on that front. “The [vaccines] have now been so widely used, including in pregnancy, that we've been able to identify side effects that occur on the order of about one in a million cases,” she explains. “I would say that so many people have been vaccinated now it's very unlikely we [will] find a new side effect, and if we did it would be a very very rare one.”
As an immunologist, Male stresses that the benefits of getting vaccinated while pregnant extend, as far as your baby’s health is concerned, to after their birth. “Although the vaccine itself doesn’t cross the placenta, the protective antibodies that your body makes do,” she explains. “Studies have shown that these antibodies reduce the chance that your baby will catch Covid, or get very sick from Covid, in the first six months of their life.”
On the other hand, Male cautions that if a baby is born early because of Covid infection, that could have impacts on them for the rest of their lives.
Dr. Cynthia Murdock, M.D., a fertility specialist at Illume Fertility in Connecticut, agrees that vaccinating yourself against Covid-19 is the best move for you and your baby. “Sometimes it can be difficult to know if you are doing the right thing, [given] there is so much misinformation surrounding the Covid-19 vaccine,” she says. “Remember that OB-GYNs have dedicated their careers to treating women and their unborn babies and would never recommend a treatment that is not safe. If you have concerns or questions about vaccinations and pregnancy, always speak with your doctor and get the facts.”
There’s so much misinformation surrounding Covid, these experts say, and one thing they encounter often is the belief that Covid vaccines can actually infect you with Covid. “[These vaccines] cannot make anyone sick with Covid-19, including people who are pregnant or their babies,” Garcia emphasizes.
The experts all note that it is never too late to get vaccinated — both for your sake, and your baby’s — or boosted, if you are due for one. “We have very good safety data from every trimester, including the first, so there’s no need to wait until after the first trimester,” says Male. “If you haven’t been vaccinated or boosted yet, it’s never too late — even if your baby is due any day!”
Male, V. (2022 SARS-CoV-2 infection and COVID-19 vaccination in pregnancy. Nat Rev Immunol 22, 277–282 ). https://doi.org/10.1038/s41577-022-00703-6
Hui L, Marzan MB, Rolnik DL, Potenza S, Pritchard N, Said JM, Palmer KR, Whitehead CL, Sheehan PM, Ford J, Mol BW, Walker SP. (2022) Reductions in stillbirths and preterm birth in COVID-19-vaccinated women: a multicenter cohort study of vaccination uptake and perinatal outcomes. Am J Obstet Gynecol., https://pubmed.ncbi.nlm.nih.gov/36336084/
Ahlia Sekkarie, PhD, MPH Rebecca Woodruff, PhD, MPH . (2022), Characteristics and treatment of hospitalized pregnant women with COVID-19, AJOG, https://www.ajogmfm.org/article/S2589-9333(22)00147-1/fulltext
Tom T. Shimabukuro, M.D., Shin Y. Kim, M.P.H., Tanya R. Myers, Ph.D., Pedro L. Moro, M.D., Titilope Oduyebo, M.D., Lakshmi Panagiotakopoulos, M.D., Paige L. Marquez, M.S.P.H., Christine K. Olson, M.D., Ruiling Liu, Ph.D., Karen T. Chang, Ph.D., Sascha R. Ellington, Ph.D., Veronica K. Burkel, M.P.H., et al., for the CDC v-safe COVID-19 Pregnancy Registry Team (2021), Preliminary Findings of mRNA Covid-19 Vaccine Safety in Pregnant Persons, New England Journal of Medicines, https://www.nejm.org/doi/doi/full/10.1056/NEJMoa2104983
Kalafat E, Heath P, Prasad S, O Brien P, Khalil A. (2022) COVID-19 vaccination in pregnancy. Am J Obstet Gynecol. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9093065/
Dr. Victoria Male, Ph.D. and immunologist and lecturer in reproductive immunology at Imperial College London
Dr. Robyn Garcia, M.D., a maternal-fetal medicine physician at UTHealth Houston
Dr. Cynthia Murdock, M.D., a fertility specialist at Illume Fertility