Pregnancy alters how the immune system works, meaning pregnant people are more at risk of severe illness from COVID-19. The COVID-19 vaccine reduces this risk.

There is no evidence that the vaccine is unsafe for the parent or fetus. In fact, research so far suggests that people who get the vaccine may have a lower risk of pregnancy complications, such as preterm birth and pregnancy loss.

For this reason, doctors advise people to get a COVID-19 booster during pregnancy.

In this article, we will explore whether and when people should get a COVID-19 vaccine during pregnancy, whether they are safe, and the side effects.

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Generally, health experts recommend that pregnant people get the COVID-19 vaccine, or a booster, during pregnancy.

A 2023 retrospective study of over 100,000 pregnancies in the United States found that people who received the vaccine had:

Another potential benefit of getting a COVID-19 vaccine during pregnancy is that it may offer some immunity to the newborn baby.

The Centers for Disease Control and Prevention (CDC) notes that the COVID-19 vaccine causes the body to make antibodies, which help protect against the virus that causes COVID-19. These antibodies may also pass to the baby.

People can get the COVID-19 vaccine at any time during pregnancy.

COVID-19 vaccines become less effective over time. In addition, new variants of COVID-19 have emerged since the original vaccine appeared.

This is why doctors recommend that, even if a person has had the standard number of COVID-19 shots, they get an additional booster during pregnancy.

Ideally, people should get the COVID-19 vaccine as early in pregnancy as possible. If a person has recently had their first or second COVID-19 shot, they need to wait several weeks before having the next one. The exact timing will depend on the type of vaccine they had.

It is safe to have the COVID-19 vaccine alongside others, such as the flu shot. People can also get it while breastfeeding.

The COVID-19 vaccine can cause side effects, but they are usually temporary and mild. They affect pregnant and nonpregnant people in similar ways.

Some common side effects include:

  • pain, swelling, and redness or other color changes at the injection site
  • fatigue
  • headache and muscle pain
  • nausea
  • fever

These symptoms are a sign the vaccine is working to stimulate an immune response. Few are any cause for concern.

However, a fever from any cause can have links to pregnancy complications. A healthcare professional can advise on using acetaminophen, in moderation, to reduce fever if it occurs.

Rare side effects and reactions

Rarely, people have more serious reactions to COVID-19 vaccines, such as an allergic reaction. However, if a person has already had COVID-19 shots without any reaction, the risk for this is very low.

There may also be an association between mRNA vaccines for COVID-19 and myocarditis and pericarditis, which are types of heart inflammation. However, these conditions are rare, and they are treatable.

Previously, another type of vaccine was available in the United States, known as the J&J/Janssen vaccine. This vaccine is no longer available because of concerns that it may increase the risk of Guillain-Barré syndrome and thrombosis with thrombocytopenia syndrome.

Below are some common questions about the safety of the COVID-19 vaccine during pregnancy.

Does the COVID-19 vaccine affect pregnancy?

There is no evidence that the COVID-19 vaccine negatively affects pregnancy or fertility. COVID-19 vaccines do not contain any live virus, so they cannot cause COVID-19 in either the birth parent or the fetus.

A large 2022 study in Canada found no association between COVID-19 vaccines and numerous birth and postpartum complications. People who received the vaccine were no more likely to hemorrhage, need a C-section, or have infants who required intensive care than those who did not.

Does the COVID-19 vaccine cross the placenta?

A preprint of a 2022 study found no evidence of mRNA vaccine in the placenta or cord blood after delivery. The study focused on 20 people who received COVID-19 vaccinations in late pregnancy.

However, this study has not undergone peer review yet.

Does the COVID-19 vaccine cause preterm birth?

There is no evidence that the COVID-19 vaccine increases the risk of preterm birth. In fact, studies have found that it may decrease the risk.

Long-term effects or complications from the COVID-19 vaccine are rare.

Research is ongoing, but so far, there is no evidence that exposure to the vaccine during pregnancy causes long-term health problems in children.

A 2024 study of over 196,000 infants in Sweden and Norway followed parents and their babies for 4 weeks after birth. The study found no association between vaccine exposure during pregnancy and any of the following:

  • bleeding
  • blood clots
  • infection
  • nervous system disorders
  • digestive, respiratory, or circulation problems
  • death

The risk of neonatal mortality was slightly lower, as was the risk of other conditions, such as brain injury due to a lack of oxygen and bleeding in the brain.

If a person gets COVID-19 during pregnancy, it can be more severe than usual. For instance, a person may:

  • have more severe symptoms
  • be more likely to spend time in a hospital
  • be more likely to need intensive care or a respirator
  • have a higher risk of preterm birth or pregnancy loss
  • have a higher risk of death

The risk is higher in those with other health conditions, such as diabetes.

Sometimes, people who get COVID-19 develop lingering symptoms that continue after the initial infection. This is known as long COVID.

A 2023 study of just under 200 people suggests that, between March 2020 and April 2022, the prevalence of long COVID was similar in pregnant people as in the general population. However, the effects of long COVID on people caring for newborns may be especially difficult to manage.

Staying up-to-date with COVID-19 vaccines lowers the risk of developing long COVID.

Still confused?

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The COVID-19 vaccine is an effective way to reduce the risk of serious illness from COVID-19 during pregnancy. It may also reduce the risk of pregnancy loss and preterm birth, and it may help the fetus develop some immunity, too.

For those who have already had all their COVID-19 shots, a doctor may recommend getting a booster during pregnancy. This is because the protection these vaccines offer wears off over time. Ideally, people should get the shot as soon as they can.

There is no evidence that the COVID-19 vaccine poses any risk to pregnant people or fetuses, nor that it crosses the placenta. If a person has any other questions or concerns about the vaccines they need, they can speak with a medical professional.