Should you take the Covid-19 Vaccine if You’re Pregnant?

(Updated 12/27/20)

The FDA took an important step on Friday by authorizing the Emergency Use for Pfizer-BioNTech’s COVID-19 vaccine.

Recognizing the risks inherent in COVID-19 infection can be significant, while those identified to date for its vaccine appear to be low, they have not advised against vaccination during pregnancy. However, its important to note that have they not specifically approved the vaccine for use in pregnancy. That’s because we have only limited animal and human data on use of the COVID-19 vaccine during pregnancy or breastfeeding.

This is incredibly frustrating to those of us who care from women of reproductive age. Some have gone so far as to call it a massive oversight in the research and regulatory process around COVID-19 vaccines. Indeed, it makes no sense, for a number of reasons –

1. There is nothing in the vaccine that raises concerns about fertility or poses excess risk to a pregnant woman or her fetus. Data from studies in rats has found no adverse effects of the Moderna COVID-19 vaccine pregnant females or their offspring.
2. We have years of experience safely providing vaccination to millions of women during pregnancy. (Think Flu vaccine, for one.) Even those vaccines designated as unsafe in pregnancy have not been found to cause excess maternal or neonatal morbidity or mortality when accidentally given.
3. Pregnancy is considered a high risk condition for severe covid-19 infection.
4. Women make up a large percentage of the healthcare worker population, at risk for COVID-19 infection, and to date constitute the largest percentage (73%) of healthcare workers infected with CVOID-19.
5. Finally, maternal vaccination is an effective and efficient way to provide immunity to newborns at birth and throughout breastfeeding.

Still, one must acknowledge that this fast-track vaccine process is on a timeline that may make it less than perfect, and the FDA has done a great job of moving the vaccine forward with little compromise of safety. I can totally understand why they would stop short of recommending the Covid-19 vaccine, and am grateful that at least for now, they have not prohibited its use during pregnancy and breastfeeding.

What We Know about Pfizer’s Covid-19 Vaccine and Pregnancy

• We do not know yet whether or not Pfizer’s COVID-19 vaccine crosses into the placenta to the fetus and do not yet have developmental and reproductive toxicity (DART) data from animal studies on Pfizer’s COVID-19 vaccine. These results are expected mid December. We now have animal data on the Moderna Vaccine use in pregnant rats, and no adverse effects on pregnancy was found. The theoretical risk from this vaccine is extremely low.

• There is nothing about Pfizer’s COVID-19 vaccine’s contents, mechanism of action or manufacturing process that suggests it will impact fertility or be harmful in pregnancy. Here’s how it works. It is not a live or even attenuated whole virus vaccine. It is a piece of manufactured messenger RNA (mRNA) that gets taken up into the recipient’s muscle cells. These cells read the message and manufacture a protein identical to the spike protein on the COVID-19 virus. The body then sees that protein as foreign and makes antibodies to it. (Pretty cool, huh?…) The mRNA is degraded rapidly, and does not enter the nucleus of a cell, so it has no potential for harm once its target protein is made.

• Twenty three pregnancies have occurred during the Pfizer COVID19 vaccine trial, 12 in the vaccine group and 11 in the placebo group. We should have outcome data within a year, though we do know that two pregnant women in the placebo group had miscarriages.

So. You’re Pregnant. Should you get the COVID-19 vaccine or not?

Talk to your doctor. Together, you’ll need to weight your risks of covid-19 infection against the as yet unknown, but likely low risks of the vaccine in pregnancy. Here are the most obvious scenarios and my thoughts about them. If you have others, feel free to comment.

• If you are a pregnant front line healthcare worker, you’re going to be first in line for the vaccine, and may opt to get it as soon as it’s offered to you, especially if you also have co-morbidities that increase your risk for severe Covid-19 infection. On the other hand, assuming you have adequate PPE and use it consistently, your risk of acquiring COVID-19 on the job is low. Animal reproductive toxicity data is just a few weeks away and you may just want to wait for that data before accepting the vaccine. But please, use PPE properly and consistently, never ever take your mask off when around others outside the home, and practice social distancing both in and outside of the workplace. Data are beginning to suggest that most covid infections among healthcare workers at this point in the pandemic are acquired in the community or from household members, and not from exposure to infected patients.
• If you are a pregnant essential worker, you may opt to get the vaccine if your job exposes you to risk of Covid-19 infection, especially if you work in sub-optimal conditions in regards to PPE or social distancing. That I even wrote that makes me ashamed – no one whose job places them at risk of infection should be working in anything less than optimal conditions. But I’m not naive, so if you’re at risk on the job and pregnant, and want the vaccine, by all means you should be able to get it. On the other hand, you may want to wait for further data. Talk it through with your obstetrician to make the choice that seems best for you in your circumstances.
• If you’re pregnant and otherwise healthy and working from home in an isolating household, with no plans to do otherwise during your pregnancy, your risk for Covid-19 infection is low. You’re not going to be top of the list for the vaccine anyway, so it’s likely we will have reproductive toxicity data by the time the vaccine is offered to you. That will make your choice much more informed, easier to make and certainly less stressful. Please continue to isolate as much as possible, wear your mask and practice social distancing whenever you venture outside the home.
• If you’re pregnant and your main COVID-19 risk is living with someone who is a healthcare or other front line worker, the choice is obvious. If they are willing to do so, ask your partner or housemate to get vaccinated as soon as possible. It protects not just them, but you and your unborn child.
• If you are pregnant and also in a high risk group for severe Covid-19 infection, such as obesity or diabetes, you may want to seriously consider getting the vaccine when it’s offered to you. If you are not an essential worker, you probably won’t have access to the vaccine until after the reproductive toxicity data is released. Assuming it’s reassuring, there will be even fewer arguments to make against vaccination.
• If you’re considering pregnancy. This is easy. Get the vaccine as soon as its made available to you. Remember it’s two doses 21 days apart, so allow yourself time to complete the vaccine series before you become pregnant.

Bottom Line

The Covid-19 vaccine is here. Though we do not have definitive safety data in pregnancy, it’s going to be available to pregnant women. It’s up to you whether or not you’ll accept the vaccine. Discuss the risks and benefits of vaccination vs, your own risk for Covid-19 infection and make the choice that’s right for you.

Additional Resources

• Society for Maternal Fetal Medicine (SMFM) Statement on Covid-19 vaccination
• ACOG Comments to ACIP regarding Covid-19 vaccine and pregnancy
• FDA Briefing Document for EUA of Pfizer Covid-19 vaccine. Everything you need to know about the vaccine.
• FDA Briefing document on the Moderna Covid-19 vaccine
• FDA Fact Sheet for Pfizer-BioNTech Covid-19 Vaccine Administration
• CDC – Use of Pfizer-BioNTech COVID-19 Vaccine:Clinical Considerations. Nice slide presentation covering most clinical scenarios.
• What exactly is in Pfizer’s Covid19 vaccine? Great article written for the lay public.