It’s understandable if you have questions about the COVID-19 vaccines. And if you’re contemplating pregnancy, or actively trying to get pregnant, social media posts may have caused you to feel concerned about possible side effects.
In particular, you may have seen viral social media posts warning women that the COVID-19 vaccines may make you infertile, which is not what you want to hear when you’re yearning for the sound of your baby’s heartbeat on a future ultrasound.
The good news? These rumors aren’t rooted in science, and in truth there’s plenty of strong evidence that the COVID-19 vaccines are safe for all women, whether they’re trying to get pregnant, are currently pregnant or are thinking about getting pregnant at some point in the distant (or not so distant) future, experts say.
Here’s what you need to know so you feel comfortable scheduling your shot when you become eligible.
How did the COVID-19 vaccine infertility rumors start?
A myth linking one of the COVID-19 vaccines with infertility has made the rounds on various social media platforms and blogs.
The rumor originated from a letter written to the European Medicines Agency by a German physician and a former Pfizer employee. The letter requested that the clinical trials of the Pfizer vaccine be stopped in the European Union until the company could provide more safety data.
The duo wrote that they were concerned that spike proteins found in COVID-19 were similar to a spike protein in the placenta called syncytin-1, and that antibodies developed from the vaccine might, in theory, cause the body to attack the placenta, leaving women infertile. Their petition spread like wildfire on social media, with posts claiming that the vaccine “causes female sterilization.”
“I’ve had family members and friends call me asking about these rumors because a friend of a friend is trying to get pregnant and is frantic,” says Oluwatosin Goje, M.D., an OB/GYN at the Cleveland Clinic and member of the What to Expect Medical Review Board. “But with a little bit of digging, these concerns are easy to dispel.”
What do leading experts say about COVID-19 vaccines and fertility?
These claims are not at all borne out by science. ”There is currently no evidence that any vaccines, including COVID-19 vaccines, cause fertility issues — problems getting pregnant,” CDC Director Rochelle Walensky wrote in an article contributed to What to Expect. ”You do not need to delay or decline COVID-19 vaccination if you are hoping to become pregnant.”
Leading experts from the American College of Obstetricians and Gynecologists (ACOG), the American Society for Reproductive Medicine (ASRM) and the Society for Maternal-Fetal Medicine (SMFM) all joined together to release a statement this past February stressing that there is no evidence that the COVID-19 vaccine can lead to loss of fertility.
While fertility was not specifically studied in the clinical trials of the vaccine, the groups point out that no loss of fertility has been reported among trial participants or among the millions of women who have received the vaccines since their authorization, nor have any signs of infertility appeared in animal studies.
In addition, the two spike proteins found in the COVID-19 virus and in the placenta are different enough that it’s highly unlikely that your body would get confused between the two, points out Dr. Goje.
“The term ‘spike protein’ is relatively new to us all, so a lot of laypeople hear the word and don’t completely understand what it means,” she explains. “But even the physicians themselves who wrote the original letter acknowledged that there was no evidence that antibodies against the spike protein of COVID-19 would also act like anti-Syncytin-1 antibodies.”
What’s more, if the German physician’s theory was true, it would show up as increased miscarriages rather than trouble conceiving, as the issue would lie with the placenta, Dr. Goje adds. Yet data doesn’t bear this out.
“We saw absolutely no evidence of this in animal model studies, and the data collected from the CDC now from pregnant women who got the vaccine shows this isn’t happening,” she reassures.
How do the COVID-19 vaccines work, and how do we know they’re safe?
To understand why the COVID-19 vaccines are considered safe, including for women trying to get pregnant and those who are pregnant, it may help to take a crash course in how they work.
Two of the authorized COVID-19 vaccines, the Pfizer/BioNTech and Moderna vaccines, are mRNA vaccines. They contain messenger RNA, or mRNA, a genetic material that tells your body how to make proteins. In this case, it teaches your cells how to make a piece of the spike protein found on the surface of the virus that causes COVID-19.
After that happens, your immune system realizes that the protein doesn’t belong in your body, and begins to build an immune response and make protective antibodies, just like it would if you were naturally infected with COVID-19.
Contrary to some rumors, mRNA vaccines don’t contain the live virus, and they also cannot enter the genome of a cell.
“Researchers have been studying mRNA vaccines for decades for diseases such as flu, Zika and even cancer, so we have plenty of strong safety data,” says Mark Payson, M.D., an OB/GYN, reproductive endocrinologist and fertility specialist at CCRM Northern Virginia in Vienna, and member of the What to Expect Medical Review Board.
Viral vector vaccines
The Johnson & Johnon/Janssen Pharmaceuticals vaccine is slightly different. Viral vector vaccines like this one use a disabled version of a live virus to deliver genetic material from the COVID-19 virus into your body’s cells.
Once it does that, the vaccine gives your cells instructions on how to make the COVID-19 spike protein, just like the Pfizer/BioNTech and Moderna vaccines do.
Its adenovirus platform (known as AdVac) has also been used for years in the development of the company’s Ebola vaccine, as well as in HIV, RSV and Zika vaccine candidates, so its safety data is strong, notes Dr. Payson.
What should you know about the COVID-19 vaccines if you’re trying to get pregnant?
Leading experts including the CDC, ACOG and SMFM agree that anyone who is pregnant, trying to conceive or breastfeeding should get the COVID-19 vaccine.
As of August 2021, the Pfizer/BioNTech vaccine has gotten full approval from the Food and Drug Administration (FDA), with the Moderna and J&J vaccines to follow, according to experts. All three vaccines are already authorized for emergency use by the FDA.
Normal side effects include tiredness, headache and pain on the arm where you received the shot. A National Institutes of Health study also found that menstrual cycle length increases approximately one day in women who receive a dose of the COVID-19 vaccine — a small, temporary change within the range of normal variability.
What’s more, tens of thousands of pregnant women have been vaccinated, and groups including the CDC, ACOG and SMFM say there is plenty of real-world evidence showing that the vaccines are safe and effective during pregnancy.
“We know getting COVID-19 when pregnant is a significant risk factor for miscarriage, and that pregnant women are more likely to end up in the ICU and even die than age-matched women who aren’t pregnant,” Dr. Payson says.
The COVID-19 vaccine is available to everyone in the U.S. free of charge, regardless of immigration status or whether or not you have health insurance. To find a COVID-19 vaccine site near you, visit Vaccines.gov.