Status of COVID-19 Vaccination, Pregnancy, and COVID-19-Related Pregnancy Complications

Note: The Pregistry website includes expert reports on more than 2000 medications, 300 diseases, and 150 common exposures during pregnancy and lactation. For the topic Coronavirus (COVID-19), go here. These expert reports are free of charge and can be saved and shared.

The COVID-19 pandemic has been with us for two and a half years and for more than half of that time —since December, 2020— safe, effective vaccines against SARS-CoV2 (the virus that causes COVID-19) have become increasingly available to an expanding number of groups. The latest group to become eligible for vaccination are children ages 6 months to just under five years, which is in addition to those ages five years and older who were already getting vaccinated, as were pregnant women. Since early in the pandemic, here on The Pulse, we have been warning you how pregnancy is a risk factor for the development of severe COVID-19 and that COVID-19 increases the risk of adverse pregnancy outcomes, notably preterm birth. Recent research, published this year, confirmed studies from last year which show that pregnant women, especially if unvaccinated, have an elevated risk of developing a severe case. It does not suggest that pregnancy makes it easier to become infected with SARS-CoV2 in the first place. However, it does show that if you do get infected, being pregnant makes it more likely that you’ll need to be hospitalized. Vaccination removes most of this risk, just as it removes most of the risk of others who have risk factors that can make COVID-19 a more severe disease. Without COVID-19 vaccination, a pregnant woman who becomes infected has a high risk that she’ll require oxygen, including high-flow oxygen, CPAP, or mechanical ventilation.

To add to this, research published over the past few months has supported earlier findings and has added accumulating evidence that infection with SARS-CoV2 during pregnancy increases the risk not only of preterm birth, but also of preeclampsia and stillbirth. Along with the need for high-flow oxygen and other breathing measures comes the need for various medications. But vaccination prevents such a severe course.

If you are pregnant or recently pregnant and had COVID-19 during pregnancy that required medical treatment (e.g., monoclonal antibodies or an antiviral such as remdesivir or molnupiravir), join the COVID-19 International Drug Pregnancy Registry (COVID-PR). This study is sponsored by Pregistry and is the world’s largest one on medications for COVID-19 and pregnancy.

A few months into the COVID-19 vaccine era, because of concerns circulating in pop culture, we had to develop a good number of posts to explaining that the COVID-19 vaccines were indeed very safe in pregnant women. Since that time, science has confirmed previous hypotheses that researchers had offered suggesting that maternal antibodies against SARS-CoV2 would be available to protect the fetus and also the nursing newborn. Over the past several months, studies have come out demonstrating that this is the case. Getting vaccinated during pregnancy against COVID-19 will protect your baby by way of antibodies that your immune system will make against the SARS-CoV2 virus. Research completed this year also confirms the presence of antibodies against the virus in the breast milk of mothers who have had COVID-19, but also in mothers who have been vaccinated.

Let’s conclude this post by discussing where we are in 2022 with respect to pregnant women and COVID-19 vaccines. As you know from our discussions, there are many different COVID-19 vaccines approved in the various countries around the world. In a few limited cases, notably the Johnson and Johnson (Janssen) vaccine, recommendations have changed since the early days. The Janssen vaccine is no longer considered to be a good choice, especially for women of childbearing age, not only because the single dose regimen turned out to be less effective than originally thought (thus making boosters even more important for J&J vaccine recipients than for others), but there is a small risk of blood clots occurring in veins, including large veins that receive blood leaving the brain. In the United States, most vaccinated people have received one of the mRNA vaccines (Pfizer-BioNTech, Moderna). The primary series of these vaccines consists of two shots, separated by at least 3 weeks for Pfizer and 4 weeks for Moderna, but the interval can be expanded to 8 or 12 weeks, depending on the country. Your third dose, the booster, should then come five months after your second dose.

If you are pregnant and received any brand of a COVID-19 vaccine during pregnancy, join the COVID-19 Vaccines International Pregnancy Exposure Registry (C-VIPER). This study is sponsored by Pregistry and is the world’s largest one on COVID-19 vaccines and pregnancy.

By now, however, you have been hearing about a fourth dose —a second booster— and wondering if you should have one, as a pregnant women, or as someone who is trying to become pregnant. Generally, it is thought that you have very good protection with three doses. Even from the first two doses, in a healthy person, which means most pregnant women, the vaccine protects extremely well against the development of severe COVID-19, the kind of COVID-19 that puts people in the intensive care unit and threatens life, and for which pregnancy is a risk factor. On account of pregnancy being a risk factor, the recommendations are also very clear at this point that you should have at least the third dose, meaning one booster.

As for a second booster —a fourth shot— obstetricians are recommending this certainly to those pregnant women who have health risk factors other than pregnancy. Otherwise, the jury is still out. If your third shot was many months ago, or a year ago, the levels of antibodies circulating in the blood have dropped down making it easier to develop mild COVID-19 if you become infected. But your long term immunity, which depends on memory cells and protects you against severe disease, should be fine. Getting a fourth shot will indeed boost your antibodies and give you added protection against mild COVID-19, but only for a few months. It’s really your call, but here’s a caveat. While you may not need the fourth shot yet for your own immunity, recent study suggests that the temporary antibody boost that you’d get from a fourth shot, if that shot is about four weeks before you deliver (give or take a week), will provide your newborn with added protection. That alone is a reasonable rationale for discussing a fourth dose —and the timing of that dose— with your doctors.

David Warmflash
Dr. David Warmflash is a science communicator and physician with a research background in astrobiology and space medicine. He has completed research fellowships at NASA Johnson Space Center, the University of Pennsylvania, and Brandeis University. Since 2002, he has been collaborating with The Planetary Society on experiments helping us to understand the effects of deep space radiation on life forms, and since 2011 has worked nearly full time in medical writing and science journalism. His focus area includes the emergence of new biotechnologies and their impact on biomedicine, public health, and society.

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