EXCLUSIVE: Covid-19 Vaccines and Infertility- Is there a link? An expert’s view of the evidence | Isaac Glatstein, MD, MSc

There is quite a bit of misinformation currently circulating on blogs, social media and various on-line platforms regarding the safety or lack thereof of the various Covid-19 vaccines and its potential impact on fertility.

The purpose of this communication is to address those concerns and to separate myth from fact and to remove the shroud of fog that has unfortunately collected over this important topic.

It should be noted that there are a myriad of worthwhile questions regarding Covid-19 including who should and should not be vaccinated, the long-term effects of the vaccine among many other topics. However, we will sharpen our focus and deal solely with the potential impact of the 2 currently available vaccines namely the Pfizer and the Moderna products that have been approved by the FDA as an EUA (Emergency Use Authorization) on human fertility and conception. The situation on the ground is that many women of childbearing age are either delaying vaccine administration due to fertility concerns or else foregoing it altogether. We wish to explore if this trend is based in fact.

In one of the very few peer-reviewed scientific articles addressing Covid-19 beliefs among a large population whichwas recently published in the Swiss Journal Vaccines, the authors determined that more than 25% of respondents firmly believed that the vaccines were designed to inject trackable microchips into recipients and furthermore, were believed to cause infertility. So, you may rightly ask, how is it possible, in today’s day and age, with near instantaneous access to all sortsof valid scientific information, that such a far-fetched idea would take root in one of every four individuals?

Furthermore, a nursing home facility in Ohio reported that 60% of staffers have declined their injections and decided to take a “wait and see” attitude. And these are health care professionalslooking after our most vulnerable populations!

It is important to understand the genesis of this discredited rumor, who perpetuated it and where it all began. First, there is the background of people who were already saying that Covid-19 was nothing more than a simple flu and/or was a conspiracy on the part of the pharmaceutical industry or the government. Against this backdrop of skepticism emerged a shadowy German epidemiologist/vaccine skeptic named Wolfgang Wodarg who, together with a former Pfizer employee, put in a petition to the European version of the FDA, the EMA (European Medicines Agency) requesting that they delay approval of the Pfizer/BioNTech vaccine. Their argument rested on the shaky and unproven hypothesis that the spike protein of the SARS CoV2 virus and a protein necessary for placentation, syncytin-1, which is important in sustaining a pregnancy, shared a common sequence. They incorrectly hypothesized that when the Covid-19 vaccine produced an antibody against the actualvirus, that antibody would also be directed against the syncytin-1 protein, and pregnancies would be unable to be established. Of course, true to form, the anti-vaccination groups embraced this theory with glee and delight, and it soon made its rounds on anti-vaccination blogs, websites, and social media. Several platforms that policed content for authenticity removed these claims after it was found to be factually incorrect.

So, the question remains, is there any biological basis to this placental protein cross reactivity that the anti-vaxxers are proposing? Is there any scientific merit to their position? Is there any reason for women to avoid taking the vaccine for fear that they may not be able to have children? Or men for that matter? This is a very important question to address and we will look at the evidence.


First, let’s talk about the shared sequence between the spike protein on the surface of the SARS CoV-2 virus and the placental protein in question. Molecular biologists describe the similarity between them akin to two completely different phone numbers, but both happen to share a single digit. There would be no way to dial one number and reach both individuals. As anyone who has studied basic molecular biology knows, even one change in one base pair of a strand of DNA can have drastically different outcomes for that individual (think sickle cell anemia or cystic fibrosis) let alone a completely different sequence that happens to share one common base pair. So, scientifically, this theory does not hold water. In fact, the German scientist/anti-vaxxer himself stated in his petition that there is no actual scientific evidence that antibodies against the spike protein would also act against the placental proteins and in fact, is just a theory.

The other hypothesis circulating regarding a potential negative impact of the vaccines on fertility stem from the use of nanoparticle technology which is the delivery vehicle to supply the body’s cells with the actual mRNA vaccine. The nanoparticles used in both the Pfizer and Moderna vaccines are composed of an outer lipid shell which is impermeable to water and protects the RNA from being destroyed before it can reach the cells and initiate the antibody production process. An unfortunate post on Facebook claimed that these nanoparticles had the potential to harm both male and female infertility. However, the reality is that these nanoparticles are not new to the drug production industry and have been used for over 20 years in the routine delivery of a variety of pharmaceuticals with no discernable negative impact. The nanoparticles used in the delivery of most drugs as well as the current COVID-19vaccines are lipid nanoparticles whereas nanoparticles containing heavy metals such as silver or titanium were found to affect the fertility of laboratory animals but only when injected directly into their venous system, a very different particle and a very different entry method which cannot be extrapolated to the current Coronavirus vaccines.

Another related but debunked claim has been that the mRNA vaccines alter human DNA. This is not the case as mRNA never enters a cell’s nucleus, which houses our DNA and therefore cannot affect the genetic material of any individual. The mRNAremains in the cytoplasm and encourages a portion of the spike protein to be synthesized and thereby stimulates one’s immune system to create antibodies to fight this spike protein. This in turn, confers immunity to that individual.

Animal studies, which were conducted on both mice and macaque monkeys as part of the safety trials for the vaccinesand of course are not a substitute for actual human clinical trials but are a prerequisite for human trials to start, did not demonstrate any impact on fertility rates including litter size, weight of the pups or any other measurable parameter.

Now, how about data from actual individuals who have taken the vaccination and what has that information yielded in terms of fertility? So, the 37,000 test volunteers who were administered the vaccine during the clinical trials were requiredto be not pregnant as this was an exclusion criterion and was confirmed by negative pregnancy testing upon study entry. However, upon completion of the study after 2 rounds of the vaccination, apparently 23 women conceived, most likely unintentionally. It is instructive to note that of those 23 women who did become pregnant, 12 were in the vaccine group and 11 were in the placebo group, having received a sham injection. In addition, the only woman who suffered a pregnancy loss in the clinical trials of the vaccine was in the placebo group and did not receive the actual vaccine. In summary, among this very large and diverse group of study volunteers, there was no differences in fertility rates, albeit unplanned, between those that did and those that did not receive the vaccine series and the only miscarriage was in the unvaccinated group.

Furthermore, if you look at the estimated 70 million Americans who have been infected with the virus (approximately 20% of the total US population), one would have expected to see an epidemic of infertility if the placental protein theory were even remotely accurate, since the antibodies produced by natural immunity would likewise affect syncytin-1 as well as the vaccine created immunity. So, although the baseline infertile population of about 10-15% of couples still unfortunately continues, we have not seen an increase in these numbers of infertile women in the past year since Covid-19 was first took root in our communities. To summarize this point, experts state that if the actual virus and subsequent immune response does notseem to alter fertility rates, why would a narrower targeted vaccine be expected to do the same?

In addition, if the nanoparticle theory was accurate, then we would also expect to see a higher rate of fertility issues among those who have already been vaccinated in the trials and in the current round of vaccines, which of course has not happened.

So, the theories of the “placental protein” and the “nanoparticles” do not pass the test of what is known as “the law of biological plausibility” and are most likely not credible.

On the other hand, pregnancy itself is now considered a high-risk feature and women who conceive and then acquire the Covid-19 syndrome during pregnancy are more likely to develop a severe infection than non-pregnant women and are more likely to be hospitalized, more likely to require an ICU, and more likely to have a fatal outcome, again compared to non-pregnant women.

Researchers at the Yale University School of Medicine have analyzed antibodies in women who have been infected with Covid-19 and have found no evidence to support the placental protein theory and deemed it “exceedingly unlikely” that the vaccine would impact on fertility. They believe that a far greater concern is that women are having fear, anxiety and stress over the wisdom of vaccinating or not, especially when they are considering pregnancy. They concluded that women who are trying to conceive or who do wish to conceive in the future should want to get vaccinated, before pregnancy, for the health and safety of themselves and their future developing child. The group at Yale is joined by such prestigious organizations such the ASRM (American Society for Reproductive Medicine) ACOG (American College of Obstetricians and Gynecologists) and SMFM (Society for Maternal Fetal Medicine) all of whom assert that COVID-19 vaccines do not impact fertility and that “loss of fertility is scientifically unlikely”.

Of course, it is up to each woman, to gather the evidence and make up her own mind regarding the suitability and safety of the vaccine in her unique situation and if necessary, discuss any questions or concerns regarding vaccination with her trusted health provider in a shared decision-making process.

It is indeed sobering to consider, that as of today, nearly 450,000 Americans have succumbed to the Covid-19 virus and are sadly no longer with us. That sheer number should give us pause and allow us to calmly and rationally evaluated the best course of action for ourselves, our families, and our future families as well. But the science is solid and although further study is certainly required, the current evidence does not support any link between any of the current Covid-19 vaccines and the development of infertility.


Isaac Glatstein, MD, MSc is a Harvard-trained, Board-CertifiedReproductive Endocrinologist who specializes in Infertility, Assisted Reproduction, in vitro fertilization, recurrent pregnancy loss, Fertility Preservation, and minimally invasive uterine surgery. He graduated from NYU School of Medicine and completed his Residency training at the Mount Sinai Medical Center in NYC in Obstetrics and Gynecology and his Fellowship in Reproductive Endocrinology and Infertility at the Harvard Medical School/Brigham and Women’s Hospital in Boston. He was then awarded a prestigious Fulbright Research Fellowship to continue his research. He was a founding partner and an Associate Medical Director at Reproductive Science Center of New England as well as an Associate Medical Director at Boston IVF- one of the largest and most successful fertility practices in the country. He is the recipient of numerous honors and awards including Castle Connolly’s Top Doctor award, the Best of Boston Doctors award, and other accolades for research, teaching and patient care. In addition, Dr. Glatstein is one of a select group of fertility specialists who is also an expert in the laboratory side of IVF, having earned a Master’s degree with distinction in the Biotechnology of Human Reproduction and Embryology. His research was on the use of Artificial Intelligence in Embryo Selection to improve patient outcomes and pregnancy rates. He is currently working on developing a Center of Excellence for Reproductive Medicine in the area which will serve the Lakewood NJ and surrounding communities. His practice, Conceive NJ, is scheduled to open in the second half of 2021.

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  1. it is more difficult to cause damage to a person than to an animal. so even if the lab mice were affected this would not necessarily hold true for humans. also, obviously the body is not designed to self destruct so the fact that naturally occurring antibodies do not disrupt fertility does not mean that lab cultured antibodies forced in to the system will not do that, but we rely on the power of Bitachon, Tefilla, Mazel and the zechus of the Mitzvah of trying to do the right thing to protect ourselves and others that we may be spared any negative outcome

  2. During Mitosis and I suppose even more importantly Meiosis, doesn’t the nuclear membrane disappea, leaving the cytoplasm and mRNA and DNA free to interact? In the presence of reverse transcriptase the mRNA could indeed alter our DNA.

  3. During Mitosis and I suppose even more importantly Meiosis, doesn’t the nuclear membrane disappear, leaving the cytoplasm and mRNA and DNA free to interact? In the presence of reverse transcriptase the mRNA could indeed alter our DNA.

    • No, it still could not alter DNA. There is simply no mechanism in the human cell to integrate RNA into DNA, nor is there any way for RNA to be used as a template for DNA synthesis (with the exception of reverse transcriptase of HIV and Hepatitis B viruses, which can only encode sequences specific to HIV and HBV)

    May Hashem Bless you and your family!
    Impressive resume!
    I am sure many will harshly criticize this article but that is expected!
    There are many more pro-vaxxers out there who are the majority!
    THANK YOU SO MUCH!!!! I have been hearing so much garbage for way to long!!!!!

  5. Dr. Glatstein,

    Thank you for the clarity. Thank you for taking the time to put us all at ease. It’s wonderdul to have such an accomplished Dr in the actual field being discussed to speak to us through this forum rather then other people with whatever backgrounds spewing their advice and opinions.

    We need to separate myth from fact and you so brilliantly did that. I cannot imagine our community has anyone in this field as accomplished as you are who will disagree with you. Sadly though, many non medical experts and self appointed scholars will no doubt argue. Hopefully we are all smart enough to make the correct choices about who to listen to.

  6. R’ Yitzchok, your mesiras nefesh for those suffering from fertility challenges is astounding. B’H you have the knowledge to refute this nonsense about the vaccines.

  7. perhaps if there is damage to the cells which are made of millions of molecules, regardless of DNA and RNA , a good stem cell treatment would regenerate the integrity , longevity of the cells making them more robust youthful and aid in the shedding of anti oxidants and foreign intruders, and the rebuilding of healthy robust cells.

  8. To Dr. Glatstein: What is your recommendation for pregnant women? There seems to be much confusion as to which, if any, trimester, the vaccination should/should not be given. It would be a great chesed to clarify this. Thank you.

  9. hi.
    there is a halacha that no one on hearth object.
    Safeck nefashot la houmha.
    so doctor or not, doesn’t matter.
    maybe there no safeck ,so they Need to take full responsibility for any consequence.

  10. We only have 12 pregnant women who were in the studies that were vaccinated because they didn’t know they were pregnant. So if one feels that’s enough safety evidence.. would one take a med that had no safety data while pregnant? There are safe options that the doctor didn’t address for treatment: hydroxychloroquine w zinc or quercetin w zinc .

    • Rachelle,

      In Israel some 1.7 MILLION+ have already been vaccinated. This is a country with a very high level of the UK variant.
      Of those 1.7 million, only 300 still got covid after both doses. Only 16!! required hospitalization. They may have actually gotten covid despite the vaccine or it may have been incubating covid- in their system from before…. Either way, not a SINGLE one passed away. Out of at least 1.7 million. Now look at how many pregnant women are nebach critically ill from this variant. Is this enough data for you to stop spewing stupidity and follow the professionals who unequivocally state that there is no danger to pregnant women taking the vaccine?? Is 1.7 million enough data for you?

      • There have been many reports of severe adverse effects, including death, among Israelis who got the vaccine (same for America – check out VAERS data through medalerts.org/vaersdb/index.php)

        It is shocking at how so many people are totally unaware of these adverse events and deaths occurring around the world.

  11. We know that the first strain of covid caused many many pregnancy losses in first trimester and the new strain is dangerous for third trimester so how can we say for sure that the vaccine is safe during pregnancy because after all some of covid is in the vaccine… it was never properly tested on pregnant people so why wouldn’t people rather quarantine for three months than take an unknown vaccine… if antibiotics eye drops are not recommended for pregnant people, Bec it was never tested, how can we say that a pretty unknown vaccine is safe?

  12. According to Dr Zelenko, HCQ is safe for pregnant woman and quercetin is not although my friends know people who took quercetin when pregnant and were ok BH. No matter what a doctor’s credentials are, there is NO doctor in the world that knows how this vaccine will play out in pregnant woman in the long term BECAUSE ITS NEW and and is NOT like other vaccines to date. Therefore it would seem wise to find a safer alternative as there are between 300 and 400 pages already on the CDC vaccine adverse event reports — many very severe including r’l death from this vaccine. I just got off the phone with someone in EY who has a already heard of 4 miscarriages from the vaccine. We need to daven for a real yeshua b’karov.

    • Is it better to get COVID while pregnant and die, CV? Or have the baby be born early and pass away, CV? Or suffer from lifelong ailments?
      What exactly are you proposing?
      Have you not noticed that the sickness and death in Charedi communities is out of proportion with the general population? Should we continue to ignore medical advise?

  13. Sorry @Malka but your info is way off. I spoke to someone in EY who helps COVID cases and they said that both they and CHasdei Amram are seeing that 80% of the cases they are dealing with now are coming as a direct result from the vaccine. It’s unsure why that is, but this an absolute reality. People who stayed shelter for many months took the vaccine and very shortly after got covid. This form of covid is much harder to treat for some reason and many are dying. You probably even heard about some of those famous people who died but didnt know why (I spoke to someone trying to treat them). I noticed that since I speak to people on the front lines in EY on an almost day to day basis, a lot of the data coming in from ISrael is realy fake news even on frum websites unfortunatley. You don’t have to beleive me because i’m anonymous but you should research yourself from first hand sources and not news articles

    • Perhaps I am wrong but if so, it is not I who is wrong….. What I stated above is what I heard DIRECTLY from one of the top doctors here in the US.

    • @SorryMalka
      According to all the medical expert, it is not possible to get COVID from the vaccine. Especially since the Phizer vaccine does not have any COVID virus inside the vaccine. The people who got COVID after the first dose, were already incubating COVID before they received the vaccine. EY is in the middle of a severe wave so this is not surprising.
      What is surprising to me, however, is that you do not notice that the Charedim are getting sick and dying at a higher percentage than the general population. Think this has something to do with ignoring doctors?

  14. Dear Malka
    HaShem can put a stop to all this but this is a big test to how we respect each other despite our differences in opinion. Let’s hope that alone will bring a yeshua! The doctors in israel do not consider any deaths or COVID after vaccination to be related to the vaccine so the data u posted is not realistic. Also, there are many good doctors who are unsure of safety in pregnancy and choose to offer the safe treatments I posted. These doctors are called all kinds of names just because they don’t agree to follow the official position. We will have to agree to disagree.

  15. Thank you for dispersing the anti-vaxxer untruths to our very vulnerable pregnant women. I, as a physician, feel confident that the vaccine is safe and now even more so having read this very clear and scientifically sound post!

  16. Everything that this person wrote might be true but as soon as he starts using adjectives to describe individuals or groups of people (e.g. “shadowy” “anti-vaxers”) he lost! If what he’s saying is based on facts and the truth only, what difference does it make if the doctor is shadowy or not? And if what he’s saying is not factually strong enough to withstand “non shadowy” doctors, what good is it?

  17. If doctors knowledge were enough we wouldn’t test at all, obviously many drugs fail in the testing stage after $$$ invested despite all what doctors know…..NOTHING replaces actual testing even the most knowledgeable opinion!

  18. To Lakewood OB It’s very sad and insulting that you would label someone antivax if they question the safety of an experimental brand new vaccine. We as consumers are allowed to question and even criticize a new technology that hasn’t been tested on humans before. We are the lab rats on a global scale. I personally know 3 people that died following the vaccine. Everyone please do your research! There’s a lot of information coming from credible scientists and doctors who are against getting this vaccine. We don’t get our information from “blogs” or “social media posts”. Just because one doctor says it’s safe, doesn’t discredit another doctor who says it’s unsafe.

    • Which doctor says the vaccine is unsafe? And let’s keep in mind, that if someone died *after* the vaccine, that does not mean they died *from* the vaccine. Correlation does not determine causation.
      The world is laughing as the charedi population ignores all medical advice and is slowly killing themselves off.

        • Higher COVID rates among charedi population has been on numerous news sites, I can’t post the links here, but I am providing three examples you can look up.
          BBC has an article titled “COVID: London’s Orthodox Jews have ‘one of the highest rates in the world’
          Times of Israel has an article titled “Nearly 1-in-4 new virus patients is Haredi […]”
          And if you only like Charedi publications: Mishpacha Magazine published this two weeks ago as well. Israeli doctors puzzled as to why majority of COVID patients are Charedi, and why they are dying at higher rates.

      • There are many doctors who feel the vaccine has not been tested enough, but they are being censored. THere are also rabbis who say it has not been tested enough: “Why do all these rabbis warn against getting the covid-19 vaccine” on Rodefshalom613.org

        And here is a question: If correlation does not determine causation, why is it that when elderly people or people with health issues died and had coronavirus in their bodies, it was assumed that they died from the virus and not from their pre-existing health conditions or age? And they added to the count of covid deaths.

  19. @GL — according to your logic, which is really the mainstream logic right now, there IS NO WAY right now to prove the vaccine is unsafe because even if a person dies 20 mins after the vaccine, they could always claim it wasn’t related ie. he had a heart attack, allergic reaction etc. Even though the heart attack and allergic reation happened as a result of the vaccine… Therefore for now, we need to look at the VEARS report and realize that MANY people are having severe reactions and its wise to WAIT until there is even more data.

  20. @cant prove
    This seems to be a common misconception. The vaccine studies continue for first few YEARS of a new vaccine . Even after the official studies are complete, vaccines are continually monitored. That is exactly why the VEARS system was set up. Yes, actual side affects can and are proven, when that happens vaccines are pulled from the market. ( In fact, one COVID vaccine candidate was pulled for side affects.)
    If a person wants to wait and see that is absolutely their free choice. However a high-risk individual (including pregnant women) who waits on the vaccine may be taking their life in their hand.

  21. @Wondering
    Where are you getting your information that the first COVID caused “many many pregnancy losses”? Do you have actual data or an actual doctor to back this claim?

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