Pregnant women are at increased risk of severe illness from COVID-19, meaning that catching the virus while pregnant or shortly after giving birth increases their chances of requiring hospitalization, being admitted to an intensive care unit, or being put on a ventilator.
Although multiple studies have shown that the COVID-19 vaccines are safe and effective for pregnant women and their babies, pregnant women have lagged behind other groups in getting vaccinated against the virus. According to the Centers for Disease Control and Prevention data, only 70% of pregnant women in the U.S. have completed their primary series of the COVID-19 vaccine before or during pregnancy.
What is most concerning for doctors and health officials is that many of those who are vaccinated have not received a booster dose. So far, only 15% of pregnant women have received the new bivalent booster shot since it became available three months ago.
Dr. Sarah Pachtman, a maternal fetal medicine physician who practices high-risk obstetrics at Northwell Health, the largest health care system in New York state, told Yahoo News that one of the main reasons pregnant women are hesitant to get the COVID-19 vaccine is because of inaccurate information being spread online.
“There is so much misinformation that's disseminated all around the internet,” she said.
When the mRNA vaccines, such as Pfizer and Moderna’s shots, first became available in late 2020, safety data in pregnancy was limited because pregnant women were not included in the clinical trials. This, however, is not unusual. When most vaccines are being developed, they are usually tested first in healthy adults. But the lack of initial safety data, Pachtman said, allowed for misinformation to spread quickly and create mistrust in the vaccine.
“There was a very politically driven and socially driven discussion around how quickly the vaccine was tested and how quickly it came out, and what the possible safety implications of the vaccine were,” Pachtman said. “It was challenging, because it was a new vaccine platform ... and so just all of the chitchat and all of the discussion in the background [was] just very confusing.”
Two years later, multiple large-scale studies have demonstrated the safety of the vaccine in all trimesters of pregnancy, as well as in the preconception and postpartum periods. The CDC, as well as two leading organizations representing specialists in obstetric care — the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine — strongly recommend the COVID-19 vaccine for pregnant women. However, hesitation among pregnant women to get the shot has persisted.
Pachtman said doctors should increase confidence in the vaccine among pregnant women by explaining why it is important that they get the shot, as well as the benefits it provides for the mother and the fetus.
Why are pregnant women at higher risk for severe illness with COVID-19?
Several studies have found that when compared to pregnant women without COVID-19, pregnant COVID-19 patients are at increased risk for adverse pregnancy outcomes, including preterm birth and stillbirth.
Pregnant women can also die from COVID-19. According to a new government report, pregnancy-related deaths have spiked nearly 80% since 2018, and COVID-19 was a contributing factor in a quarter of the 1,178 maternal deaths reported last year.
Pachtman explained that pregnancy causes a lot of changes in the maternal immune system, as well as in the body of the pregnant person. These changes can continue shortly after birth and make pregnant women and new moms more susceptible to getting very sick with COVID-19.
“We have data from other viral infections and upper respiratory infections in pregnancy and from COVID, that suggests that pregnant patients are at increased risk of severe and critical illness from respiratory viruses in general,” Pachtman said.
Other doctors have said that SARS-CoV-2, the virus that causes COVID-19, can affect the lungs and the cardiovascular system, which are already strained during pregnancy. "As the uterus grows, there is less and less room for the lungs. That's why pregnant women often feel short of breath. And that affects your pulmonary function," Denise Jamieson, chair of obstetrics and gynecology at Emory University School of Medicine, told Science in 2020.
Pregnancy can also cause other medical conditions, such as gestational diabetes and high blood pressure, which also put a person at risk for COVID complications.
Why should pregnant women get vaccinated and boosted against COVID-19?
There are several reasons why women who are pregnant or planning to become pregnant should get the COVID-19 vaccine and the updated booster, Pachtman said. The first is that it is safe and effective. Second, it protects the mother and the baby from severe illness, she explained.
“I always explain to my patients, I say, ‘Look, you can still be exposed to and carry and get a virus even if you have a vaccine that protects you. However, the point of the vaccine is for your protection against severe or critical illness. You can't have a healthy pregnancy if your body isn't healthy. That fetus is living inside your uterus. It's kind of like the house: If the house is falling down, you can't continue to carry a healthy pregnancy,’” Pachtman said.
“By getting the vaccine, you might still get a cough and a fever and not feel well and have body aches, but you're majorly decreasing your risk of needing ICU care, being put on a ventilator, needing an early delivery and needing medication,” she added.
Studies have also shown that pregnant women who receive the COVID-19 vaccine can pass protective antibodies to the fetus. One of these studies was published last month in the American Journal of Obstetrics & Gynecology MFM. Patchman said the research showed that mothers can do something to protect their babies in those first months of life. Infants are not eligible for the COVID-19 vaccine until they are 6 months old.
“These moms are giving their babies antibodies via passive transfer across the placenta and/or from breast milk,” she said.
Antibody levels found in breast milk were “dramatically increased by the booster,” and offered protection to babies for at least 12 months, according to the study.
At a press briefing last week, Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, said it was important for pregnant women to receive their flu shot and stay up to date with their COVID-19 vaccinations, including getting the bivalent booster.
The U.S. is currently experiencing an uptick in COVID cases, and hospital systems across the country are also struggling with an overwhelming number of patients sick with RSV and influenza infections.
“This rise in cases and hospitalizations is especially worrisome as we move into the winter months, when more people are assembling indoors, with less ventilation,” Walensky said. She explained that someone who has received the primary COVID-19 vaccine series is considered fully vaccinated, but that without the new bivalent booster, that person is not necessarily fully protected this winter.
The shot, approved in September by the CDC, was developed to target the BA.4 and BA.5 Omicron variants, as well as the original strain of the virus. Officials have said the booster is essential to lower the risk of severe illness and death from COVID-19.
“I encourage patients to get the vaccine, because you don't want to get sick at all in pregnancy. Why would you want to put your pregnancy even at a little bit of risk?” Pachtman said.
As for when is a good time for pregnant women to receive the shot, she said, any time is a good time.
“If you haven't had the vaccine yet, the best time to get it is now. If you're due for your booster, the best time to get it is now.”