Update: Fertility and the Covid Vaccine

As fertility specialists and OBGYNs, providing guidance to individuals who are pregnant or trying to conceive and protecting them from misinformation is at the core of our mission. As a healthcare worker who was 18 weeks pregnant when NYC became the epicenter of the COVID-19 pandemic, I deeply empathize with the struggle of having to make crucial health decisions for oneself and their family, using limited data. As we approach the 1.5 year mark, there have been over 30 million infections in the US, and 600K deaths. So much about the infection is still a mystery - why are some more severely impacted than others? We now know that serious illness and death from COVID-19 is significantly more likely in those who are immunocompromised, elderly, and pregnant. Pregnancy is, itself, a state of immunocompromise - the immune system dampens its response to allow an embryo to implant and develop into a growing pregnancy. In later stages of pregnancy, the growing uterus means there is lower lung capacity, which can make it harder to withstand lung infections or to adequately ventilate a patient with respiratory compromise. Women who contract the SARS-CoV2 virus in pregnancy are definitely at increased risk of severe infection requiring hospitalization, mechanical ventilation, and of needing to be delivered prematurely to facilitate lifesaving treatments.

After a year of social distancing, isolation, masking, and uncertainty, came the advent of vaccines against SARS-CoV2 at the turn of 2021. Swift Emergency Use Authorization from the FDA was followed by waves of vaccination, first to the healthcare workers and other essential personnel who could not do their jobs from the safety of their homes. At this time, it had become clear that pregnant women and their fetuses were a high risk group - but the major question which loomed was whether those who were pregnant or breastfeeding could safely receive the vaccine? At this time, there was no large-scale data because the initial vaccine trials by Pfizer and Moderna purposely excluded those trying to conceive or already pregnant. This is the norm for any trial assessing the efficacy and safety of a new drug/therapy. However, there were about 2 dozen women in the Pfizer trial who DID conceive during the study - they were followed and only 1 of them had an adverse event (miscarriage) - a participant in the placebo arm. While these numbers were small, it was a good sign that the vaccine was safe and acceptable to take while pregnant. Moderna had previously studied the question using lab rats - and found that vaccination did not impact the ability to conceive, stay pregnant, or the health of offspring, based on their animal model. Many of the drugs which doctors routinely permit patients to continue during pregnancy have little to no human safety data but are thought to be okay to continue if the benefits outweigh theoretical risks/effects, and if animal data is reassuring. This is very common and not a new practice. Based on all of this, healthcare providers and major womens’ health organizations in the US- the American Society of Reproductive Medicine (ASRM), American College of OBGYN (ACOG), Society of Maternal Fetal Medicine (SMFM), and the CDC- unanimously stated that pregnant individuals and even those trying to conceive or breastfeeding SHOULD be offered the vaccine. At that stage (January/February 2021) many pregnant healthcare workers and teachers began getting vaccinated. The CDC created an app, called ‘v-safe’, which tracked these individuals for pregnancy outcomes and adverse events. As we hit milestones such as the first 10-30K pregnant women being vaccinated, and the rate of new infections plummeted, confidence grew and vaccine uptake continued. All the while, there was trouble brewing on the internet and social media. Insidious rumors and myths about the vaccine causing women to become sterile began perpetuating from the dark corners of the world wide web. It all started from a blog called Health and Money News, authored by two individuals with absolutely no expertise in the field of women’s health or fertility, who claimed that there could be a cross reaction whereby the antibodies produced in response to the vaccine could attack a placental protein, causing infertility and/or miscarriage of an existing pregnancy. THIS IS NOT TRUE and there is absolutely no evidence to support this claim. These damaging and false claims have severely stunted the vaccination effort and led to the abysmal rate of vaccination in pregnant women. As of May 2021, the CDC reported that only 16% of pregnant women have been vaccinated.

This is why it is so important to keep talking about vaccination and fertility/pregnancy and the data that has now become available to reassure us about the safety and effectiveness of the vaccine. Here’s everything you need to know:

How the vaccines work
All of the currently available vaccines work by teaching your body to make the outer spike protein which coats the SARS-CoV2 virus. Pfizer/Moderna are messenger RNA (mRNA) vaccines which deliver particles of mRNA to your cells in the arm muscle which then teach the cells of the body to make the spike protein which is then recognized by the immune system, resulting in the production of antibodies against the spike protein. This leads to long-term ability of the body to recognize and ward off the SARS-CoV2 virus. The other vaccines (ie. J&J, AstraZeneca) do the same thing but use a different vehicle to deliver the genetic code/instructions to make the spike protein. All of the components of the vaccine (mRNA, lipid particles) are rapidly broken down in the body and do not have the ability to circulate in the body long-term or cross the placenta. Even the spike protein which is made by your own body is transient and broken down in a matter of days.

Vaccines do not cause infertility
It has been confirmed without a doubt that there is not a similarity in structure between the spike protein and any placental proteins, therefore there is NO risk of a cross reaction between antibodies against the spike protein and the placenta. Anecdotally, we as a practice have recommended vaccination wholeheartedly from day 1 - MANY of our patients are vaccinated. We analyze our internal data constantly and can attest to there not being any change in pregnancy rates or the incidence of miscarriage in patients prepandemic versus now. We presented our preliminary data from Spring 2020 at a national conference, showing no difference in the success rates of embryo transfer cycles from the years before the pandemic compared with the first 2-3 months of the pandemic, where up to 25% of NYC’s population was thought to be infected. A recent study confirmed this by comparing frozen embryo transfer outcomes from individuals who had antibodies from the SARS-CoV-2 vaccine (n=35), antibodies from actual infection (n=20), and in those without antibodies (n=88) and demonstrating that there was NO difference was in pregnancy rates or miscarriage.

Vaccination is safe and protective whether pregnant or breastfeeding
Pregnancy is an independent risk factor for more severe illness and death from COVID-19. Mothers who contract COVID while pregnant are more likely to need premature delivery to save their lives or for the well-being of the baby. Those who survive a severe infection may have long-haul disability/symptoms which severely limit their ability to work, function, or care for their children. These are very real risks which can be prevented by vaccination. The New England Journal of Medicine published a study reporting the outcomes of individuals vaccinated during pregnancy from December 2020 to February 2021, using CDC data from the v-safe vaccination health registry and the Vaccine Adverse Event Reporting System (VAERS). At that early stage, more than 3900 pregnant participants were enrolled, of which more than 800 had completed their pregnancy/delivered a baby. Reassuringly, the adverse outcomes (ie. miscarriage, stillbirth, preterm delivery etc.) in vaccinated pregnant individuals were similar to the baseline incidence reported in studies prior to the pandemic. At this point, hundreds of thousands more pregnant people have been vaccinated in the US with continued reassurance and no red flags- sadly, this cohort still represents only ~16% of those who are pregnant.

The choice to get vaccinated should be based on protecting oneself from severe infection and death from COVID-19 and to protect the vulnerable populations (unvaccinated children and immunocompromised individuals who may not benefit from the same level of protection as those with a healthy immune system). Beyond this primary focus, is the promising possibility that vaccination during pregnancy might protect an unborn child and future newborn from SARS-CoV2. Studies have shown the presence of antibodies in cord blood (coming from baby) at time of delivery from a vaccinated mother and that the earlier in pregnancy that infection/vaccination takes place, the higher the levels of antibody in babies at time of delivery. Breastfeeding presents another route by which one could pass protective antibodies to their unvaccinated children. Several studies have collected milk from vaccinated breastfed mothers and shown the presence of IgG and IgA antibodies. We don’t yet have concrete data on whether the antibodies delivered to a fetus/baby via the placenta or breastfeeding are protective against COVID-19 and if there is protection, how much and how long it may last. But we know it is safe to be vaccinated while pregnant and breastfeeding - so these secondary benefits could be an added and important bonus of vaccination. We will surely learn more about this as time goes on, but for now it seems highly plausible that these antibodies could be protective and beneficial. You can read the full study referenced above here:

At this point in the pandemic, the choices have become clear - you can either choose vaccination or take on the very high likelihood of contracting the SARS-CoV2 virus - especially with the rapid rise of highly infectious variants such as delta. Knowing what we know about infection in pregnancy, and based on how the vaccines work and the data from the hundreds of thousands of pregnant women who have been vaccinated, we recommend everyone get vaccinated- while trying to conceive, while undergoing fertility treatment, while pregnant (any trimester), and even when postpartum and breastfeeding. There is no reason to forego the vaccine. The vast majority (99%) of severe infections and deaths from COVID-19 are occurring in the unvaccinated. This is a preventable tragedy. If I had access to a protective vaccine during my pregnancy, I would have accepted it in a heartbeat, without an ounce of hesitation. If you are at all concerned or hesitant about vaccination due to concerns about your fertility or pregnancy, please talk to you doctor and visit the following websites of reputable health organizations:


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