If You're Pregnant, Your Immune System Changes—But Does That Make You More Susceptible to COVID? We Asked Doctors


The Centers for Disease Control and Prevention (CDC) just announced new recommendations that strongly urge pregnant women to get the COVID-19 vaccine. "Pregnant and recently pregnant people are more likely to get severely ill with COVID-19 compared with non-pregnant people," the CDC says in its recommendation.

The guidelines come just weeks after the American College of Obstetricians and Gynecologists (ACOG) updated its guidance to make a "strong recommendation" that pregnant people get vaccinated against COVID-19.

A big question many pregnant women have is…why? While the CDC has strongly urged all Americans over the age of 12 to get vaccinated against COVID-19, it particularly stresses how important it is for people who are immunocompromised to get the shot.

Does the new guidance mean that pregnant women are immunocompromised? It's actually a little more complicated than most people realize. Here's what you need to know.

RELATED: COVID-19 Vaccines May Not Work as Well for Immunocompromised People—Here's What We Know So Far

What happens to your immune system when you’re pregnant?

During pregnancy, certain parts of your immune system are enhanced while other parts are dampened to allow you to grow and protect a fetus inside you.

"During pregnancy, there are many immunological and physiological changes that occur," women's health expert Jennifer Wider, MD, tells Health. "The immune system is often in flux and as a result, pregnant women may be more vulnerable to infections, including viral respiratory infections like COVID-19."

These immune changes are perfectly timed to help protect both you and your baby, while allowing you to carry the baby to term, suggests a small study from 2017 published in the journal Science Immunology. Experts back the study results up.

Are-Pregnant-Women-Immunocompromised-GettyImages-1132546763 Are-Pregnant-Women-Immunocompromised-GettyImages-1132546763 , MD, ob-gyn at the Winnie Palmer Hospital for Women and Babies in Orlando, Florida, tells Health. "In the beginning, there's a pro-inflammatory state, which is helpful for implantation. Then it goes into an anti-inflammatory state, which is helpful for the growth of the baby. In the third trimester, it reaches another pro-inflammatory state to prepare for childbirth."

RELATED: If You're Immunocompromised, You Are at a Higher Risk of Coronavirus—Here's What That Means

What does it mean to be immunocompromised?

A person who is immunocompromised has a weakened immune system, according to the National Cancer Institute (NCI). These people have a lowered ability to fight infections and other diseases, which can be caused by certain diseases or conditions like AIDS, cancer, diabetes, malnutrition, and certain genetic disorders. Immunosuppression can also be caused by some medicines or treatments, including radiation therapy, organ transplant, and anti-cancer drugs.

So are pregnant women immunocompromised?

Not exactly. "It's kind of nuanced," David F. Colombo, MD, a Michigan-based ob-gyn and division chief of maternal fetal medicine at Spectrum Health, tells Health. "The answer is no, but with an asterisk. Your immune system just works differently when you're pregnant."

"I don't think we should officially call pregnant women 'immunocompromised'—as for example, women who have cancer and are getting chemotherapy, or folks who are born with immunodeficiency diseases," Mary Jane Minkin, MD, a clinical professor of obstetrics and gynecology and reproductive sciences at Yale Medical School, tells Health. "However, many folks think of pregnant women as somewhat immunocompromised because they are 'tolerating' a foreign presence in their uterus." A baby has genes from a totally different person as well, Dr. Minkin points out, and a pregnant person's immune system system has to be able to tolerate that on an immunological level.

"Pregnant women are considered to be a 'special population group' due to the state of the immune system during pregnancy," Dr. Wider says. But while pregnant women aren't immunocompromised per se, "a pregnant person's body is undergoing immune system changes and is not operating the same way a non-pregnant person's is," Dr. Wider explains. As a result, she adds, "her body cannot defend against infections in the same way."

In terms of COVID-19, Dr. Minkin says that pregnant people are susceptible to serious illness for reasons outside of their immune response. "One problem with COVID and related illnesses that has nothing to do with the immune system is that pregnant women have this 'thing' in their abdomens that pushes up the diaphragm, so lung space is compromised," she explains. "If a pneumonia sets, in they will mechanically have worse problems ventilating."

Pregnancy also causes a "tremendous strain" on your cardiovascular system, with pregnant women pumping an increased volume of blood. If a woman has an underlying heart condition on top of pregnancy and then develops COVID-19, "she will be in a very bad way," Dr. Minkin says.

RELATED: What Is a Weak Immune System? Here's How Doctors Explain It

What can pregnant women do to stay healthy?

Dr. Colombo stresses the importance of getting vaccinated against COVID-19. "The biggest risk to pregnant women right now is catching COVID," he says. "The vaccine is safe; COVID is not."

There's also this to consider, per Dr. Minkin: "Besides protecting the woman, there is evidence that [the mom] will pass on some antibodies to her baby."

It's also important to wear a mask when you're indoors in areas where there is a substantial or high rate of COVID-19 spread, wash your hands, and practice social distancing, Dr. Wider says. "Taking these precautions will go a long way in keeping a mom and her baby safe," she adds.

Overall, Dr. Greves says she advises patients to be "as careful as possible, because there are other infections floating around other than COVID-19 or the flu." But, Dr. Greves says, pregnant women also shouldn't panic over this. "Recognize that you're doing all you can do and try not to be too anxious about it," she says. "If you're doing all you can, enjoy your life and the beautiful baby growing inside."

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