Ask a Scientist: Will the COVID-19 vaccine affect my fertility?

Will the COVID-19 vaccine affect my fertility?

The short answer to that question is NO.

Current data and scientific studies indicate that the COVID-19 vaccines

• do not affect your ability to become pregnant, and
• are safe to receive during pregnancy

In fact, experts are recommending vaccination, whether you are pregnant now or you are planning to become pregnant in the future.

But there has been a lot of misinformation circulating about vaccines and fertility, and it’s one of the top concerns raised by many patients.

That means we have tons to talk about! Let’s get to it.

When the COVID-19 vaccines were approved, one of the first things that popped up was a false association between the spike protein on the virus and syncytin-1, which is a key protein in placenta development.

• The claim – which I’ll say right now, is completely false – suggested that training your immune system to defend against the coronavirus will ultimately cause your immune system to attack syncytin-1, thereby damaging the placenta and putting your pregnancy at risk.

In reality, these two proteins have very different structures. There was never a risk that the COVID-19 vaccines would—or even could—have this effect.

Unfortunately, this rumour – and other misinformation like it – has stuck around quite stubbornly, leading a lot of people to worry about their own fertility or even their children’s future fertility.

But the data from studies taking place all over the world do not justify these concerns. If anything, the data can be quite reassuring.

• For example, Dr. Deshayne Fell and her colleagues at BORN Ontario have examined data from 40,000 pregnancies. They found no patterns of adverse pregnancy outcomes with vaccines.
• We also have early data from the Canadian COVID-19 Vaccine Registry for Pregnant and Lactating Individuals—also known as COVERED. This is a national survey on COVID-19 vaccines in pregnancy that I’m leading out of the University of British Columbia alongside colleagues from across the country.
  • Analysis is ongoing for this study, but the data to date from over 5,000 volunteers do not raise any safety concerns. In fact, it shows no adverse events related to receiving the vaccine and no increase in pregnancy complications.

I could go on and on! These are sound studies that are well designed and have been scrutinized by experts. They are all contributing to a tremendous body of evidence that tells us these vaccines do not interfere with your ability to become pregnant or to carry a pregnancy to term.

So let’s move on now to talk about why vaccination is not only safe but is actually recommended for those of you who are pregnant or hoping to become pregnant.

In addition to studying the vaccines and pregnancy, researchers have been looking at the impacts of COVID-19 infection on pregnancy.

And I’m one of those researchers! I’m the lead for a national project studying COVID-19 in pregnancy.

When the pandemic hit, we knew that we would need data to get a better understanding of what happens if someone gets sick with COVID-19 during pregnancy, what impacts it might have on the pregnancy, how those impacts might affect the baby’s health outcomes, and whether the virus can be transmitted from parent to child (in pregnancy or postpartum).

Early in the pandemic, these were all question marks. We were talking about a new virus, after all.

And so we launched this national surveillance project across Canada, with 6 provinces sharing data so far, to help us answer those questions.

Similar projects are happening in other countries, too—and from a data perspective, that’s exactly what we need. It means we are building a deep understanding of what’s happening both here in Canada and around the world.

The recent data shows that, basically, if you look at a group of pregnant patients who end up with a COVID-19 infection, about 7.8% will require hospitalization because of it and 2% will be admitted to the ICU.

Now, it’s easy to look at that and think, ‘hey, those are still small percentages, no big deal!’ But you have to compare those figures to what’s happening in patients who are not pregnant in order to get a sense of whether something is riskier in pregnancy or not.

Based on where these figures stand now, you are 3 times more likely to be hospitalized if you get sick with COVID-19 during pregnancy (compared to if you get sick with COVID-19 when you’re not pregnant). Similarly, you are 6 times more likely to end up in the ICU if you get COVID-19 during pregnancy.

We are also seeing higher rates of preterm birth in pregnant patients with COVID-19 (The rate of babies being born too early is 11% for those with COVID-19, compared to 6.8% in those not infected).

Studies are also showing that if you get COVID-19 during pregnancy, the inflammation associated with fighting the virus may cause abnormal changes in the placenta. So, while the vaccine does not lead to placenta issues, the real virus can cause harm.

What all of this is telling us is that yes, COVID-19 infection during pregnancy puts you at an increased risk for these negative health outcomes.

So, generally, thanks to the wealth of scientific data that we now have available to us and the studies that I’ve described, experts are recommending vaccination – whether you are pregnant now or if you’re planning to become pregnant in the future.

This is all about making informed decisions—based on facts—so I hope that this information about COVID-19 vaccines and fertility has been helpful.

If you have questions or concerns, I encourage you to talk to your health care provider about the options that will be best for you.

Special thanks to:
Deborah Money, MD, FRCSC

Professor, Obstetrics & Gynaecology
Faculty of Medicine & School of Population and Public Health
University of British Columbia

Clinician Scientist
Women’s Health Research Institute