Updated on October 1, 2021.
If you’re pregnant, recently pregnant, or plan to become pregnant in the future, you need a COVID-19 vaccine. Researchers at the Centers for Disease Control and Prevention (CDC) issued an official advisory, strongly recommending vaccination for pregnant individuals, those who are recently pregnant and/or currently breastfeeding, those trying to get pregnant, and those who might become pregnant in the future.
The agency’s call for “urgent action” follows new data about more than 125,000 COVID-19 cases during pregnancy. These cases resulted in more than 22,000 hospitalizations and, tragically, 161 deaths. Twenty-two of those deaths—the pandemic’s record one-month high—occurred in August 2021.
Babies, too, are at risk if their parent is unvaccinated. The CDC reported a higher risk among pregnant people with COVID-19 for preterm births and the need for newborns to go to a neonatal ICU.
The CDC’s push for vaccinations echoes recommendations already made by the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine.
But so far, fewer than one-third of pregnant people have been fully vaccinated either before or during their pregnancy. The CDC also reports that about 97 percent of coronavirus-infected pregnant people who were hospitalized either for illness or for labor and delivery had not been vaccinated.
What we know so far about vaccine safety in pregnancy
If you’re pregnant or breastfeeding, it’s understandable if you’re concerned about the possible risks that a COVID-19 vaccine could pose to your baby. It’s true that the vaccines available for use in the United States were developed in record time and the monitoring of these vaccines for safety and effectiveness will continue for the foreseeable future.
But the harms of not being vaccinated are clear. Evidence is also mounting that the Pfizer and Moderna mRNA vaccines are safe for pregnant people and their babies. According to the CDC, the data so far suggest the benefits of vaccination during pregnancy outweigh any known or potential risks.
For example, evidence emerged that vaccination doesn’t affect miscarriage rates in a study posted online August 9 prior to peer review and cited by the CDC. The researchers analyzed the CDC’s v-safe After Vaccination Health Checker and pregnancy registry. Among 2,456 pregnant people who received an mRNA COVID-19 vaccine either before conception or at up to 20 weeks’ gestation, there was no increased risk of miscarriage.
Results of another independent study also support the safety of vaccination during pregnancy. The small study, published in March 2021 by the American Journal of Obstetrics and Gynecology, compared the effects of Pfizer’s and Moderna’s COVID vaccines among 84 pregnant participants, 31 who were lactating and 16 who weren’t pregnant.
Researchers, including those from Brigham and Women’s Hospital and Harvard Medical School, reported that both vaccines confer a robust immune response in pregnancy—and the immunity can be transferred to unborn babies. The two-dose vaccines generated strong antibodies to fight COVID infection in all the study participants with no associated harms to the fetus.
Antibodies were present in babies who were born after their parent received either one or two vaccine doses. The researchers also detected antibodies in breast milk and umbilical cord blood.
Despite the small size of the study, it provides valuable preliminary data, according to Jeanne Sheffield, M.D., director of the division of Maternal-Fetal Medicine and a professor in the Johns Hopkins Medicine Department of Gynecology and Obstetrics.
“It certainly allows us to be able to talk to patients and tell them we have some early data showing that it is safe in pregnancy. It has allowed us to be a little more reassuring to patients who are concerned,” she says. “We tell them upfront there’s still not a large study showing safety, but it is coming.”
Earlier this year, too, CDC researchers compiled preliminary results based on data from the Vaccine Adverse Event Reporting System (VAERS), a national vaccine safety monitoring system, and its v-safe After Vaccination Health Checker and pregnancy registry.
Reports from 35,691 pregnant people who received their shots between December 14, 2020 and February 28, 2021 showed rates of miscarriage, premature births and other complications among the vaccinated were unchanged from those reported before the pandemic began.
Although research on the long-term safety and effectiveness of the COVID-19 vaccines is ongoing, the study, published on April 21 in the New England Journal of Medicine, is reassuring.
Pregnant people at higher risk for severe COVID-19
There’s no question that pregnant people are at increased risk for developing severe complications from COVID-19.
If you’re pregnant or recently pregnant and have COVID-19, you’re more likely than someone who’s not pregnant to experience severe illness, be admitted to a hospital, stay in an intensive care unit, be placed on a ventilator and not survive the disease, according to the Centers for Disease Control and Prevention (CDC). Preterm birth and/or neonatal ICU admission are likelier, and data also suggest higher risks for serious problems with the pregnancy and birth, including preeclampsia, blood coagulation problems, and stillbirth. Pregnant people who are infected with the coronavirus can also transmit that infection to their newborns.
Troubling information like that is why the CDC is joining the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine to advise that the vaccines be offered to pregnant and breastfeeding people. The American Society for Reproductive Medicine also advises everyone, including those who are pregnant and those trying to become pregnant, to get a COVID-19 vaccine.
Safety and efficacy research is ongoing
Dr. Sheffield regularly engages in shared decision making and risk-benefit discussions with her pregnant and lactating patients.
“We talk about the efficacy of the vaccine—how effective it is in preventing disease and hospitalizations in nonpregnant individuals,” Dr. Sheffield explains. “And then we talk about what limited data there is on risk.” She informs her patients of the available research on the vaccine’s use in pregnant people.
“We are getting more and more data,” she adds, “showing that, besides benefiting the mom, the vaccines might actually benefit the baby after the baby is born.” Sheffield also points to safety data emerging from the CDC’s v-safe After Vaccination Health Checker.
As of September 27, 2021, the CDC is closely tracking 5,104 pregnancies and counting in the v-safe COVID-19 Vaccine Pregnancy Registry. That group is a subset of over 161,000 so far who have told the CDC they were pregnant at the time of vaccination via the v-safe After Vaccination Health Checker. More data will come out as these pregnancies proceed.
The CDC encourages people to enroll in v-safe, which is open to anyone who’s received one of the three FDA-authorized vaccinations. You can sign up as soon as you receive your first vaccine.
Dr. Sheffield hasn’t seen any difference between her pregnant and nonpregnant patients’ reactions. “They’ve had the standard arm soreness, body aches, low-grade fever. We have not had anybody that has had significant side effects.” She recommends that patients take Tylenol to relieve symptoms.
What about the J&J vaccine?
Experts don’t have enough evidence to know whether this single-dose vaccine will yield similar results. The J&J vaccine is a viral-vector vaccine that’s made differently than the Pfizer and Moderna vaccines. The latter vaccines were developed using messenger RNA (mRNA) technology. The mRNA vaccines are the first of their type to be approved in the United States, but the technology has been in development for the last decade.
Don’t forget your other vaccines
With all the talk centered around COVID vaccines, don’t overlook vaccines that protect against other infections while you’re pregnant. The CDC, the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine recommend that all pregnant people get flu and TDAP (tetanus, diphtheria and pertussis) vaccines. Both vaccines are safe for pregnant people and their babies. Talk to your healthcare provider about the vaccine schedule that is appropriate for you.
Sources:
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Centers for Disease Control and Prevention. V-safe After Vaccination Health Checker. Accessed Apr. 1, 2021.
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