Should pregnant women get COVID-19 vaccines?

Dr. Anna Euser’s answer is a resounding and enthusiastic “yes.” She strongly encourages women who are pregnant to get the COVID-19 vaccines.

And, health experts with the Centers for Disease Control and Prevention (CDC) are advising anyone who is pregnant to immediately get COVID-19 vaccines.

That’s because the illness is so dangerous for pregnant women. This advice is especially critical now as the delta variant continues to cause an unrelenting wave of COVID-19 illnesses and a new variant, omicron, may be even more transmissible.

Euser is in a unique position to provide advice about the importance of vaccines during pregnancy. She’s a maternal-fetal medicine specialist at UCHealth University of Colorado Hospital on the Anschutz Medical Campus and an assistant professor of obstetrics, gynecology and maternal-fetal medicine at the University of Colorado School of Medicine.

Euser cares for pregnant women who are experiencing high-risk pregnancies — and she, herself, was pregnant during the pandemic.

Euser thoroughly researched the safety of COVID-19 vaccines for pregnant women and was thrilled to get her vaccine the first day she was eligible. She received her first dose of the Pfizer vaccine on Dec. 17 when she was 32 weeks pregnant and her second dose at 35 weeks.

Her baby girl, Nell, was born on Jan. 27 and Euser was pleased that immunities from the vaccines she received during her pregnancy crossed over to her baby.

Euser also participated in a safety study conducted by researchers at the U.S. Centers for Disease Control and Prevention (CDC) to monitor how pregnant women have done after receiving either the Pfizer or Moderna COVID-19 vaccines.

Early data from more than 35,000 pregnant women in the U.S. showed that women who received COVID-19 vaccines did not experience any unusual health problems after receiving COVID-19 vaccines. The study did not analyze pregnant women who received the Johnson & Johnson (J&J) vaccine, which in very rare instances has caused blood clots in young women. The new research from the CDC was published on April 21 in the New England Journal of Medicine.

Because pregnant women were not included in clinical trials for COVID-19 vaccines (although some study participants became pregnant during the trials), CDC experts initially encouraged pregnant women to talk with their doctors before getting COVID-19 vaccines. But, the CDC guidance on the safety of COVID-19 vaccines for pregnant women now is much more direct: “COVID-19 vaccination is recommended for people who are pregnant, breastfeeding, trying to get pregnant now, or might become pregnant in the future.”

Here’s what Euser tells her patients.

“Every pregnant woman should get the COVID-19 vaccine. It’s safe and I recommend getting it,” Euser said.

Medical experts with the American Society for Reproductive Medicine also have endorsed vaccination for pregnant women.

‘’Everyone, including pregnant women and those seeking to become pregnant, should get a COVID-19 vaccine. The vaccines are safe and effective,’’ experts at the Society said in a recent statement.

Doctors at the American College of Obstetricians and Gynecologists say that all pregnant and breastfeeding women should have access to COVID-19 vaccines. They are eager to learn more in follow-up studies.

To help pregnant women make decisions about getting the COVID-19 vaccine, Euser provides answers to frequently asked questions about pregnancy and vaccines to prevent COVID-19.

Why should pregnant women strongly consider getting COVID-19 vaccines?

Getting sick with COVID-19 can be very dangerous for pregnant women. That means prevention through a COVID-19 vaccine is especially helpful, Euser said.

“Severe COVID-19 is bad and severe for anyone, but pregnant women are at an increased risk for severe complications of COVID-19 than women of similar ages with comparable health who are not pregnant,” Euser said.

Why is a severe case of COVID-19 so challenging for pregnant women?

When women are pregnant, they can be vulnerable to infections that are hard on the lungs. When people are critically ill from COVID-19, many struggle to breathe and need to go on ventilators, which breath for them.

As a maternal-fetal medicine expert, Euser spent some time caring for hospitalized COVID-19 patients while she was pregnant.

She used high-quality personal protective equipment or PPE and felt protected from exposure to the virus that causes COVID-19.

But, Euser directly saw the impacts of the disease on patients. Some women had to be intubated while their babies were delivered and did not get to hold or bond with their newborns until after they recovered from COVID-19.

Euser wants as many pregnant women as possible to get their vaccines so they don’t become critically ill with COVID-19 and endure illness or complications during their pregnancies.

Are all vaccines safe during pregnancy?

In general, vaccines are safe during pregnancy.

“For many years, we’ve been using vaccines in pregnancy safely,” Euser said.

The exception is vaccines that use live viruses. Doctors do not give vaccines for chickenpox and measles to pregnant women.

“Otherwise, we give vaccines in pregnancy all the time. They are important for protecting the mom or the baby. For instance, we give pertussis (whooping cough) vaccine in pregnancy so the baby can get antibodies,” Euser said.

Do the antibodies from COVID-19 vaccines pass to the baby in utero?

Yes. COVID-19 vaccines help keep pregnant women safe. But, a side benefit is that the antibodies also cross the placenta and provide antibodies to the baby.

Euser loves this double benefit.

“I would have gotten the vaccine regardless of whether it crossed the placenta,” she said. “But, knowing that I could pass immunities on to Nell was an additional benefit.”

Euser said there are different types of antibodies which are known as IgM, IgG and IgA antibodies.

For pregnant women, doctors know that IgG antibodies cross the placenta to the fetus.

In breastmilk, IgAs cross from breastmilk to the infant.

“We give whooping cough or pertussis vaccines to pregnant women because the IgG type of antibody and will cross to the baby in utero,” Euser said.

Once the baby is born, other antibodies cross through breastmilk.

“We have known for a long time that one of the benefits of breast milk is that antibodies from the mom cross to the baby,” Euser said.

Is there an ideal time to get the COVID-19 vaccine during pregnancy or should a pregnant woman get the vaccine as soon as she can?

Euser is encouraging pregnant women to get COVID-19 vaccines as soon as they are able to do so.

“There has been some advice to wait until the end of the first trimester due to the possibility of fever after vaccination,” Euser said. “This was based on the potential risk of high fevers in the first trimester associated with birth defects (though this data is mixed and not convincing), so some have advised waiting until the end of the first trimester to get the vaccine.”

But, since the risk of fevers is low, Euser is encouraging patients to get the vaccines as soon as they are comfortable.

“If women are concerned about fevers, they can take acetaminophen (Tylenol) after their vaccine dose,” Euser said.

Should pregnant women get the flu vaccine?

Yes. The flu vaccine is safe and effective for pregnant women. Like COVID-19, influenza can be hard on the lungs of pregnant women. So, it’s vital for women to get the flu vaccine so they can stay as healthy as possible, Euser said.

During the H1N1 flu outbreak in 2009, pregnant women became more critically ill than others. Flu vaccines are vital to protecting pregnant women — and the rest of the population — every year.

“We recommend the flu vaccine for everyone who is pregnant,” Euser said.

I’ve heard that the Moderna and Pfizer COVID-19 vaccines are different than previous vaccines. Does that make them more or less safe for pregnant women?

The Moderna and Pfizer vaccines are a new type of vaccine, known as mRNA vaccines. But, these types of vaccines have been studied for years. Based on everything we know to date, they are safe and effective during pregnancy, Euser said.

Should pregnant women get the J&J vaccine after evidence emerged of blood clots in very rare instances?

Euser believes that the J&J vaccine overall is quite safe and there is no evidence that the vaccine is a concern in pregnancy. Like everyone, we will continue to follow the data about the risk of blood clots and recommendations may change as we learn more. But, women should have a choice. If they prefer to get the Moderna or Pfizer vaccines instead of the J&J vaccine, that should be their choice, Euser said.

Do the COVID-19 vaccines impact fertility or a woman’s ability to get pregnant?

No. Women who have received vaccines to prevent COVID-19 have not had any impacts on their fertility that we know of at this time and based on how they work we do not anticipate concerns. While the clinical trials for COVID-19 vaccines deliberately excluded pregnant women, some participants became pregnant during the trials and no women experienced any adverse impacts on their fertility or their ability to get pregnant. There also have been no reports of challenges with fertility among millions of women who have received COVID-19 vaccines since health authorities around the world have authorized these vaccines.

Health experts with the American College of Obstetricians and Gynecologists, the American Society for Reproductive Medicine and the Society for Maternal-Fetal Medicine all recommend that women who are planning to get pregnant or those who are pregnant should have access to COVID-19 vaccines.

“There is no evidence that the vaccine can lead to loss of fertility,” health experts from these leading medical groups said in a written statement.

“While fertility was not specifically studied in the clinical trials of the vaccine, no loss of fertility has been reported among trial participants or among the millions who have received the vaccines since their authorization, and no signs of infertility appeared in animal studies. Loss of fertility is scientifically unlikely.”

Are the COVID-19 vaccines safe for breastfeeding women?

Yes, Euser said.

“Based on the data we have, the COVID-19 vaccines pose no risks to women who are planning to get pregnant, who are pregnant or who are post-partum and are breastfeeding,” Euser said.

In fact, studies have shown that infants born to mothers who received COVID-19 vaccines have antibodies to COVID-19.

Euser said maternal-fetal experts strongly suspected that would be the case.

“It’s great that they proved it, but it doesn’t surprise us,” Euser said. “We know that moms pass antibodies to their babies.”

How long do antibodies to COVID-19 last for newborns whose moms received vaccines for COVID-19?

Euser said researchers will learn more over time, but she suspects that newborns will be protected for at least a couple of months if their mom received a vaccine while she was pregnant. Infants who are receiving breastmilk could receive antibodies over a longer period of time.

“It will depend on how long the mom is making antibodies. It’s probably at least six to eight weeks,” Euser said.

COVID-19 vaccines are now authorized for children as young as 5. Do you expect COVID-19 vaccines to someday be authorized for infants and toddlers?

Yes, Euser said. She hopes to see COVID-19 vaccines for infants, toddlers and young children down the road. Euser eagerly would enroll Nell in a clinical trial for infants.

How are Euser and her daughter doing?

Both Euser and Nell are doing great. Euser loved her birth experience. She arranged for all of her favorite labor and delivery providers to assist her at University of Colorado Hospital. Nell weighed 6 pounds 11 ounces and needed a little oxygen after birth, so she spent a short time in the Neonatal Intensive Care Unit.

Nell has a lot of light brown hair and bright blue eyes. Euser, 41, is a single mom and can’t wait until she and Nell can travel together. Euser is already applying for a passport for Nell.

These days at a little over three months, Nell is smiling regularly and sleeping some of the time.

“I feel really lucky,” said Euser, who recently returned to work after her maternity leave.

“New parents can be isolated during the pandemic. But, I’ve been vaccinated and my friends and family have been vaccinated. My dad is a physician and my sisters work at his practice, so the whole family has been vaccinated since Nell was born.

“Everyone in my family gets to be part of Nell’s life. We’ve been bonding and sharing happy times together and that is what I want for all of my patients. I want vaccination rates to be high and widely accepted so that all families can have that experience.”