Editor’s note: After a safety review, the FDA and CDC has recommended lifting the pause on the Johnson & Johnson vaccine. Investigators concluded that an unusual side effect involving blood clots and low levels of platelets (cells that help the body stop bleeding) occurs very rarely and does not outweigh benefits of the vaccine. For more information, see our Coronavirus Resource Center.
Now that COVID-19 vaccines are widely available in the US, pregnant people — and anyone considering a future pregnancy — have many questions around risks and benefits. At first, many of those receiving vaccines in US were healthcare workers, but the circles for vaccine eligibility have widened.
The Centers for Disease Control and Prevention (CDC), the American College of Obstetricians and Gynecologists (ACOG), and the Society for Maternal-Fetal Medicine (SMFM) agree that the COVID-19 vaccines should be offered to pregnant individuals who are eligible for vaccination.
Here are answers to some basic questions you may have about getting a COVID-19 vaccine if you’re pregnant or considering pregnancy, soon or in the future. Keep in mind that information is evolving rapidly. Your obstetric provider or medical team can advise you more fully about benefits and risks, based on your personal health risks, exposures to the virus that causes COVID-19, and preferences.
What do we know about how COVID-19 affects people who are pregnant?
COVID-19 is potentially dangerous for all people. Although the actual risk of severe illness and death among pregnant individuals is very low, it is higher when compared to nonpregnant individuals from the same age group. Those who are pregnant are at higher risk for being hospitalized in an intensive care unit and requiring a high level of care, including breathing support on a machine, and are at higher risk for dying if this happens.
If you’re pregnant, you may also wonder about risks to the fetus if you get COVID-19. Research suggests that having COVID-19 might increase risk for premature birth, particularly for those with severe illness. So far, studies have not identified any birth defects associated with COVID-19. And while transmission of the virus from mother to baby during pregnancy is possible, it appears to be a rare event.
You can read more about pregnancy and COVID-19 in this blog post.
Which vaccines are authorized?
Three COVID-19 vaccines have emergency use authorization from the Food and Drug Administration (FDA). All deliver instructions to the body that help the immune system block the virus that causes COVID-19. This can be done in different ways:
- a two-dose Pfizer/BioNTech vaccine. This vaccine uses mRNA.
- a two-dose Moderna vaccine. This vaccine uses mRNA.
- a one-dose Johnson & Johnson vaccine. This vaccine uses a harmless, modified form of the common cold virus in humans called an adenovirus.
Studies show all three vaccines are extremely effective in reducing risk for severe illness, hospitalizations, and deaths from COVID-19. They also help reduce risk for moderate illness.
You can read more about the different vaccines on the Harvard Health Coronavirus Resource Center.
What do we know about the safety of COVID-19 vaccines in people who are pregnant?
None of the vaccine trials chose to include pregnant individuals, so our direct knowledge is currently limited. Some trial participants inadvertently became pregnant, and a small number of these people received the vaccine. Further studies of vaccine volunteers who are pregnant are underway or should start soon.
The Centers for Disease Control and Prevention (CDC) is tracking more than 30,000 vaccine recipients who were pregnant at the time of vaccination. Nearly 1,800 have provided detailed descriptions of symptoms after vaccination and pregnancy outcomes. So far, pregnant people appear to have the same vaccine side effects as nonpregnant individuals. No miscarriages, stillbirths, or preterm births linked with the vaccines have been reported.
Important points about mRNA vaccines:
- When studied during animal tests, the mRNA vaccines did not affect fertility or cause any problems with pregnancy.
- In humans, we know that other kinds of vaccines generally are safe for use in pregnancy — in fact, many are recommended. The immunity that a pregnant individual generates from vaccination can cross the placenta, and may help keep the baby safe after birth.
- mRNA vaccines do not contain any virus particles.
- mRNA particles used in the vaccine are eliminated by our bodies within hours or days, so these particles are unlikely to reach or cross the placenta.
Important points about the Johnson & Johnson vaccine:
- The modified adenovirus used in the vaccine can’t replicate or cause illness. The body quickly clears it from the injection site, so it’s unlikely to reach or cross the placenta.
- In animal tests, this vaccine did not affect fertility or cause problems with pregnancy.
- Vaccines similar to this one — called adenovirus vector vaccines — have been studied in humans for HIV, Ebola, and Zika virus. Trials that enrolled pregnant people reported no harmful pregnancy outcomes.
- We know that other kinds of vaccines generally are safe for use in pregnancy — in fact, many are recommended. The immunity that a pregnant individual generates from vaccination can cross the placenta, and may help keep the baby safe after birth.
What about vaccine side effects?
One possible side effect of the COVID-19 vaccines is fever a day or two after vaccination. This occurred in about
- 1% to 3% of people after the first dose of mRNA vaccine
- 15% to 17% after the second dose of mRNA vaccine
- 9% after the Johnson & Johnson single-dose vaccine.
These fevers are generally low and can be managed with acetaminophen, which is safe to take during pregnancy. Rarely, high, prolonged fevers in pregnancy may lead to birth defects.
For more information about common COVID vaccine side effects, see this CDC resource page.
What to consider about COVID-19 vaccines if you’re pregnant
Eligibility for COVID vaccines varies from state to state. Healthcare workers with direct patient contact are typically in the first phase for vaccines, followed by other people at high risk for getting COVID or becoming very sick from it, such as first responders, essential workers, nursing home residents, people over age 75, and people with certain health conditions. Because pregnancy is considered a risk factor for severe COVID-19 illness, your pregnancy may already make you eligible for the vaccine in some states.
Assuming the COVID-19 vaccine is available to you during your pregnancy, you have several options to discuss with your health care provider.
- Get vaccinated as soon as the vaccine is available to you. You might decide to do this if you have additional risk factors for severe complications from COVID-19 (such as high blood pressure or obesity), and/or multiple potential exposures to COVID-19 from your work, your family, or your community.
- Wait until after you give birth to get the vaccine. You might choose to do this if pregnancy is your only risk factor for severe disease, and you are able to control your exposures by limiting interactions with people outside of your household and using protective measures (mask wearing, handwashing, and physical distancing).
- Consider ways to modify your exposures to COVID-19 and possibly defer getting the vaccine. Most people have some risk factors and some uncontrolled exposures. If this describes you, you still have options. You may decide to modify your exposures if possible and defer vaccination until the second trimester, when the natural risk of miscarriage is lower. Or you may choose to delay vaccination until after the baby is born.
- Wait for a traditional vaccine similar to the flu shot or Tdap vaccines. These vaccines are in development but are not yet approved in the US. Experts know much more about using these types of vaccines in people who are pregnant. However, depending on your exposures to COVID-19 and your risk for getting seriously ill if you get infected, it may be wisest to accept the COVID-19 vaccines that are available at this time.
If you are considering deferring the vaccine, ask whether vaccination will be available to you at a later date. The answer may vary depending on supplies of the COVID vaccines and vaccination programs where you live.
One more note about timing: If you choose to receive the COVID-19 vaccine during pregnancy or the postpartum period, the CDC recommends scheduling it at least 14 days before or 14 days after any other vaccination, such as a flu shot or Tdap (tetanus, diphtheria, pertussis) vaccine. Talk to your obstetric provider about the best timing for routine vaccines and your COVID vaccine during pregnancy.
What to consider if you’re thinking of becoming pregnant soon or in the future
Many people who are considering a pregnancy soon or in the future wonder if the COVID-19 vaccines affect fertility. However, there’s no evidence that they do, according to ACOG and SMFM. While human vaccine trials did not specifically study fertility, no signs of infertility were noted in animal studies.
Once the vaccine is available to you, getting vaccinated prior to pregnancy is a great way to ensure that you — and your pregnancy — are protected.
The bottom line
COVID-19 vaccination for people who are pregnant has potential benefits, and raises some as yet unanswered questions. It helps to become as informed as you can when making your decision, but realize that information may be changing rapidly. We will learn more about COVID vaccine safety during pregnancy from human studies now underway.
Meanwhile, you can stay informed by checking trusted health websites, such as those listed above, and by talking with your healthcare providers. Together you can balance the latest data on risks of COVID-19 in pregnancy, the safety of available vaccines, your individual risk factors and exposures, and most importantly, your values and preferences.
Coronavirus (COVID-19), Pregnancy, and Breastfeeding: A Message for Patients. American College of Obstetricians and Gynecologists.