Does the COVID vaccine cause infertility?

As the percentage of vaccinated individuals across the country continues to grow, so do the rumors and misconceptions about its side effects. Various news outlets and social media platforms are largely at fault for these fallacies, as they continue to circulate inaccurate and misleading information. 

Many women have speculated that the vaccine is to blame for any variation they have experienced in their menstrual cycles (i.e how heavy/light or its duration). Despite the lack of scientific evidence, many have jumped to the conclusion that this demonstrates how the vaccine adversely affects recipients’ reproductive systems. 

A common myth involves the idea that the vaccine could cause the immune system to attack syncytin-1, a protein that has a critical role in the development of the placenta during pregnancy. Since syncytin-1 and a spike protein included in the vaccine share small pieces of genetic code, fear circulated that the vaccine could also cause the body to make antibodies that reject the placenta. 

However, this misconception has been addressed in vaccine clinical trials and safety data continues to grow as more women of child-bearing age become fully vaccinated. According to the New England Journal of Medicine, research conducted on more than 35,000 pregnant women who received mRNA COVID-19 vaccines found “no evidence the vaccines have affected or harmed people who were pregnant, and there’s no evidence that the shots harm the baby or pregnancy.” 

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MU Health Care family medicine doctor Laura Morris, MD, even speaks to how vastly different these two proteins are on a larger scale. “A good analogy I’ve heard is that for your immune system to get mixed up and attack the placental protein would be like you mistaking an elephant for an alley cat because they’re both gray,” Morris said. “There is one small similarity, but the overall construction of the protein is so completely different, your immune system is way too smart to be confused by that.” 

While there is no rational, scientific reason to presume that the COVID-19 vaccine is a threat to women’s fertility, evidence does reveal there are health concerns for pregnant women who become infected with COVID-19. According to research presented by the Mayo Clinic, pregnant women who get COVID-19 are at a higher risk for having a preterm or a stillbirth and are also at a higher risk for maternal death from COVID-19. 

Although the COVID-19 vaccines are new to medicine, the technology that created them is not and women have been safely vaccinated before and during pregnancy for decades. To mitigate the risks that COVID-19 infection poses to both the mother and the child, The Society for Maternal-Fetal Medicine and the American College of Obstetricians and Gynecologists (ACOG) have both recommended that people who are pregnant have access to COVID-19 vaccines.

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