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Home » COVID vaccines and infertility – study shows no effect on ovarian function

COVID vaccines and infertility – study shows no effect on ovarian function

As a result of various tropes about COVID-19 vaccines, anti-vaxxers claim that the vaccine causes infertility. It does not, and now we have a small study that shows no effect on ovarian function that sometimes can lead to infertility in women.

The claims about vaccines and infertility are one of the go-to tropes of the anti-vaccine world. For example, they tried this nonsense with the HPV vaccine which was based on a retracted study, and they failed. They tried to claim that the tetanus vaccine caused “mass sterilization” in Africa, and they failed there too.

This time quacks like Christiane Northrop, a retired OB/GYN with no expertise in vaccine research, are trying to claim the COVID-19 mRNA vaccines from Pfizer and Moderna will cause infertility. Anti-vaxxers are trying to use some seriously twisted “logic” to get from the facts about these vaccines to a major myth that somehow, in some magical way, these vaccines will cause infertility. 

Let’s get right to the point – no, they don’t. But let me give you the science.

COVID-19 vaccines infertility
Photo by Devon Divine on Unsplash

Can COVID-19 vaccines cause infertility?

We’ll get to a paper about COVID-19 vaccines and ovarian function in a moment, but I’d like to remind everyone of why this claim should be ignored right at the top:

  1. There is simply no biologically plausible mechanism for COVID-19 mRNA vaccines to have any impact on infertility. None. As I have discussed before, the mRNA molecule does not make changes to the genetic code nor does it have any impact on anything to do with fertility.
  2. Preclinical animal studies with the Moderna and Pfizer vaccines have shown no effect on fertility.
  3. Clinical studies have shown no effect on pregnancy outcomes.
  4. Lipid nanoparticles in the COVID-19 mRNA vaccines do not accumulate in the ovaries causing infertility.
  5. By the way, for you men, COVID vaccines does not negatively affect sperm.
  6. Most importantly, the anti-vaxxers have not provided one nanogram of evidence to show that the COVID-19 vaccines have, in fact, been shown to have any impact on infertility.

I’m sure most of my readers already understand that the COVID-19 vaccines do not have any effect on infertility. But you know that if I can debunk a myth one way, I’ll debunk it in any way possible.

So let’s look at this paper.

COVID-19 vaccine and ovarian function

My favorite OB-GYN skeptic, Dr. Jen Gutner, reviewed a yet-to-be-peer-reviewed pre-print article that examined the effect of COVID-19 vaccines on women undergoing in vitro fertilization or IVF.

During the IVF procedure, the ovaries are treated with gonadotropins, such as FSH, to stimulate the development of follicles, which contain the egg along with cells that make estradiol and progesterone, which are necessary for implantation and pregnancy. The researchers looked at signs of fitness of the follicles and eggs in response to the hormone in three groups:

  1. History of COVID-19 vaccination
  2. History of previous COVID-19 infection.
  3. Neither vaccination or previous infection

Dr. Gutner explains the results:

This is a small study, only 32 patients, but it is important because it is the first to give us a look at what is happening not just inside the ovary, but inside the follicle where the fertility action is actually happening. Of the participants, nine had received at least one dose of the Pfizer – BioNtech vaccine, nine had recovered from COVID-19, and 14 hadn’t been vaccinated nor had COVID-19 (negative antibody testing). Among the nine who were vaccinated, the four had received their first dose were an average of 11.7 days from the injection (range 8-18 days) and the five who had received two doses were an average of 27.6 days from injection (range 4-46 days). As vaccine complications are almost always seen within the first 60 days this timing is important. If you are looking to find a negative effect you are unlikely to find something years after vaccination. 

The researchers found the levels of COVID-19 antibodies in the follicular fluid mirrored the levels in the blood. So the higher the levels in the blood, the higher levels in the fluid around the egg. Other work has identified antibodies from other infections in the follicular fluid, so it’s not surprising antibodies were found. but this is the first time it has been shown with COVID-19. 

And all the parameters that measure the health of the follicles and the eggs? There was no difference in terms of follicle or egg maturation, hormone levels, or other biomarkers for the vaccinated women versus those who had previously had an infection with Covid-19 versus the control group. The only difference was the progesterone in the blood was lower for the non-exposed control group earlier in the cycle, but not on the day the eggs were retrieved, and so the researchers don’t believe this was a real biological difference.  

The researchers concluded:

Hence, despite the clear evidence of intimate follicular immune exposure post infection with SARS-COV-2 or following BNT162b2 mRNA vaccine, the steroidogenic machinery of the follicle, controlling the ultimate maturation of the oocyte and its hormonal milieu, did not show any measurable difference as compared to non-exposed women. 

Now, it’s important to note that this is a very small study and it has not been peer-reviewed. Obviously, it has not been published except on a preprint server.

This study just adds to the boatload of data that the COVID-19 vaccines have no effect on infertility, compared to the absolute lack of evidence provided by the vaccine deniers.


The facts are that there is no evidence that the COVID-19 mRNA vaccines will have any effect on infertility. And it appears that there is no effect on ovarian function.

This is just another myth pushed by the anti-vaccine mob to cause fear, uncertainly, and doubt about these vaccines. 

Let’s stick with scientific facts. 



Michael Simpson

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