Now that COVID-19 vaccines are rolling out, pregnant and breastfeeding people have many questions around risks and benefits. At first, many of those receiving vaccines in US will be healthcare workers, although the circles for vaccine eligibility are widening.
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 new mRNA COVID-19 vaccines should be offered to pregnant and breastfeeding individuals who are eligible for vaccination. You can weigh benefits and risks with your doctor.
Here are answers to some basic questions you may have about getting a COVID-19 vaccine if you’re pregnant or breastfeeding — or are considering a pregnancy. Keep in mind that information is evolving rapidly. Your obstetric provider or medical team can advise you more fully, 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.
What do we know about the safety of newly available mRNA COVID-19 vaccines in people who are pregnant?
The mRNA vaccine trials did not deliberately include pregnant or breastfeeding individuals, so our direct knowledge is currently limited. Some vaccine trial participants inadvertently became pregnant; 18 of these people received the vaccine. Further information may be available in coming months.
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.
It’s also important to know that
- The mRNA vaccines do not contain any virus particles.
- Within hours or days our bodies eliminate mRNA particles used in the vaccine, so these particles are unlikely to reach or cross the placenta.
- The immunity that a pregnant individual generates from vaccination can cross the placenta, and may help to keep the baby safe after birth.
What about vaccine side effects? One possible short-term side effect of the mRNA vaccine trials (occurring within one to two days of vaccination) is fever. About 1% to 3% of people have experienced fever after the first dose of mRNA vaccine, and about 15% to 17% after the second dose. 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.
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.
Assuming the mRNA 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 have an mRNA vaccine.
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: The flu shot and Tdap (tetanus, diphtheria, pertussis) vaccines are routinely recommended during pregnancy. 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. Talk to your obstetric provider about the best timing for the COVID-19 vaccine.
What to consider about COVID-19 vaccines if you’re breastfeeding
Experts, including the WHO, believe it is most likely safe to get an mRNA COVID-19 vaccine if you’re breastfeeding. Although breastfeeding people were not included in the vaccine trials, the mechanism of mRNA vaccines and experience from other vaccines suggest this is true.
It is important to know:
- There is no virus in the mRNA vaccines. You cannot get COVID, or give your baby COVID, by being vaccinated. The components of the vaccine are not known to harm breastfed infants.
- When you receive the vaccine, the small mRNA vaccine particles are used up by your muscle cells at the injection site and thus are unlikely to get into breast milk. Any small mRNA particles that reach the breast milk would likely be digested.
- When a person gets vaccinated while breastfeeding, their immune system develops antibodies that protect against COVID-19. These antibodies can be passed through breast milk to the baby. Newborns of vaccinated mothers who breastfeed can benefit from these antibodies against COVID-19.
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. And there are no reports of loss of fertility among vaccine trial participants and millions of people who have been vaccinated since emergency use authorization was granted. So scientifically, loss of fertility is unlikely.
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 or breastfeeding 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 be learning more about COVID vaccine safety during pregnancy and while breastfeeding from animal studies now underway, and from human studies that are enrolling participants.
Meanwhile, you can stay informed by checking trusted health websites, such as those listed above, and 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.