There are several questions around the vaccine and fertility. Does the COVID-19 vaccine cause infertility? Where do health officials stand?

Myth: The vaccine can cause infertility.

The claim circulating on social media that the COVID-19 vaccine causes female infertility is FALSE and is not supported by any research. Following guidelines from the FDA, no one is excluded from receiving the vaccine, even patients who are pregnant or breastfeeding, as there are no medical contraindications to receiving this vaccine. Pregnant patients should discuss with their physician individual risk factors to make an informed decision about possible vaccinations. Current data from COVID-19 vaccine trials support the safety and efficacy of these vaccines, and the benefits of vaccination greatly outweigh the risks of not being immunized. The Society for Maternal Fetal Medicine has issued advice for those pregnant or breastfeeding.

There have been some rumors that the spike protein the body creates after vaccination to allow the immune system to recognize and fight off COVID-19 is like a protein in the placenta of pregnant mothers. While there are small areas of similarity, the proteins are very different and the response to the spike protein does not launch an immune response to the placenta that could endanger the mother’s ability to carry a baby to term.

CDC Guidance

According to the Centers for Disease Control (CDC), there’s no evidence that the authorized COVID-19 vaccines have impacts on pregnancy, and patients trying to get pregnant now or in the future can receive a COVID-19 vaccine.

Right now, health officials say the risks of the virus are greater than the risks of the vaccine, especially for pregnant women. According to the CDC, data has shown that pregnant women with COVID-19 have an increased risk of severe illness compared to women who are not pregnant. The CDC recommends pregnant women consult their healthcare providers before getting vaccinated if they have concerns.

Food and Drug Administration (FDA) Position

Infertility is not known to occur as a result of natural COVID-19 disease, further demonstrating that immune responses to the virus, whether induced by infection or a vaccine are not a cause of infertility.

American Society for Reproductive Medicine position

The Task Force does not recommend withholding the vaccine from patients who are planning to conceive, who are currently pregnant or who are breastfeeding and encourages patients undergoing fertility treatment to receive vaccination based on current eligibility criteria.

In addition, the statement addresses head-on a piece of misinformation which has been circulated by antivaccine ideologues and states that the mRNA vaccines “are not thought to cause an increased risk of infertility, first or second trimester loss, stillbirth, or congenital anomalies.”

Did pregnancies occur in the United States clinical trials of the Pfizer vaccine?

Yes, in the Pfizer trial, which included more than 37,000 people, women were given pregnancy tests before they were accepted to the study. They were excluded if they were already pregnant. During the trial, 23 women conceived, likely by accident. Twelve of these pregnancies happened in the vaccine group, and 11 in the placebo group. They continued to be followed as part of the study.

Until now, most of the data we have on the safety of the COVID-19 vaccines comes from women who participated in trials who did not know they were pregnant or from women who were aware of their pregnancy, but decided that it was still in their best interest to receive treatment. However, on April 21, the CDC published a study in the New England Journal of Medicine that reported on the outcomes of over 35,000 pregnant women who received either the Moderna or Pfizer COVID-19 vaccines. Of these participants, nearly 4,000 reported data throughout their pregnancy. Their rates of miscarriage, preterm birth, stillbirth and fetal growth restriction were all similar to what was reported in the population before the pandemic. Based on this, the CDC has recommended that coronavirus vaccines be made available to all pregnant women.

Editor's note: This blog was originally published on Feb. 4, 2021 and has since been updated.