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  • Writer's pictureFrederike Schmitz

A COVID-19 vaccine while pregnant?

Photo by Blessing Ri on Unsplash

Today I want to devote a blog to vaccinations and pregnancy.


Because I finally got my first SARS-CoV-2 vaccine! Yay! And I’m pregnant again. Yay!

To be honest I was a bit nervous to get the vaccine.

I don’t know about you, but I’ve been looking forward to this to happen for pretty much as long as we’re in the pandemic.

And when I learned that I’m pregnant again it was even more nerve wrecking.

Why? Because pregnant women are never included in regular clinical trials. Which means that when the COVID-19 vaccines received emergency authorization (hence it then officially enters the market) there was no data on its safety for pregnant women.

I suppose it’s a good thing that pregnant women are not included in clinical trials, because nobody wants to take the responsibility of adverse effects (when something bad or unexpected happens).

After all, it now concerns two beings- the mother and the child.

Supposedly the Thalidomide scandal in the 1950s and 1960s (also known as Contergan) changed a lot of how we practice medicine during pregnancy. Back then the drug was given to pregnant women to treat anxiety and sleeping problems without testing it first in a clinical trial on pregnant women.

It caused thousands of miscarriages and deformations of their babies.

Since then I guess we’re in the opposite situation now.

Doctors and pharmaceutical companies are super careful, almost afraid to test drugs on pregnant women.

And yes, that makes sense.

But it also means that there is very, and I mean very little known about the working of medicines in pregnancies.

When you’re otherwise healthy and are not relying on any medication, you don’t need to worry about it. However, when you get sick right before getting pregnant or during your pregnancy- that is a serious problem.

But it is also somewhat of a problem now with vaccines.

Since no pregnant women were included in the official clinical trials, there is no data on the COVID-19 vaccine’s safety in this group of people.

But when you do large clinical trials and vaccinate thousands and thousands of people all over the globe, by chance you’ll have a few who either signed up not knowing that they were pregnant or who become pregnant during the trial. Even though being pregnant was an exclusion criterion.

From that data it was already clear that COVID-19 vaccines seemed safe for pregnant women.

In the US they started to offer the mRNA vaccines from BioNTech/Pfizer and Moderna to pregnant women early on. A good friend of mine from the US took it when she was about 4 months pregnant. By now also the first scientific publications have emerged looking at this data and concluding that the vaccine seems safe for pregnant women.

The reason why I write ‘seems’ all the time is that we’re still missing a large clinical trial or access to bigger numbers of pregnant women to say something with more confidence. This is why multiple ‘trials’ are running in each country where pregnant women can sign up and report side effects and their general health. In the Netherlands this is done by ‘Moeders van Morgen’ (literally translated: mothers of tomorrow). In the US it’s the CDC's v-safe study

I already registered to the Dutch trial, because I believe it is essential that we have more information available on medical interventions during pregnancy (like vaccinations).

If you have more questions about vaccinations and pregnancy, I highly recommend reading this great explainer document from Victoria Male. She is an immunologist at Imperial College in the UK and is updating this document regularly.

While we now have some scientific data available, different countries still come to different conclusions.

Here is how the US, Germany and the Netherlands interpret the data and recommend vaccinations or not.

In the Netherlands the RIVM states “If you are pregnant you have a higher risk of becoming seriously ill from COVID-19, especially in the third trimester.” The conclusion: you can vaccinate when in the last trimester.

In Germany the Robert Koch Institute states “So far, there are no findings from controlled studies on the use of COVID-19 vaccines in pregnancy. Based on the recently published observations from the USA alone, the STIKO will not make a general vaccination recommendation for pregnant women”.

The conclusion: So far vaccinations for pregnant women are not recommended unless the pregnant woman has underlying health issues.

However, in the popular German corona virus podcast with Christian Drosten (nr. 86 after minute 56), he also talks about the scientific evidence of increased risk for pregnant women and says that more data might change the general recommendation at some point.

In the US the Center for Disease Control (CDC) states “Pregnant people are more likely to get severely ill with COVID-19 compared with non-pregnant people”. The conclusion: vaccinations are possible for pregnant women.

What were my reasons to decide to get the vaccine now?

During the whole pandemic I somehow had the feeling that it’s probably not the best time to become pregnant. As I thought that pregnancy would likely be a risk factor for COVID-19 complications.

Why is that? Because generally a woman’s immune system is slightly suppressed while being pregnant. That makes sense, biologically speaking, because the woman is growing another being inside of her. The last thing you want is an overreaction of your immune system towards your child. This is why pregnant woman’s immune cells are much more chilled out, tolerating more than if you were not pregnant.

Now that’s an advantage when you think about the pregnancy itself. But the moment you have an infection, it’s not that great. Because then all your immune cells need to kick into action. Fighting off whatever invader you encounter at that time. (Wait until you read my immune story for kids about that..)

In April this year a study came out that confirmed my worry. Pregnant women have indeed an increased risk of developing a more severe form of COVID-19, in comparison to non-pregnant women.

This was for me the turning point, deciding in favor of a vaccine.

The moment it was made available for me.

This in combination with the ‘preliminary’ safety reports- stating mRNA vaccines as safe in pregnant women convinced me to get vaccinated.

Well, I guess I could have waited for another couple months until I gave birth and then get vaccinated. Yes, and no.

First of all, it is actually beneficial to get vaccinated when you’re pregnant. Because of something called ‘passive immunity’.

This means that the mother-to-be will pass on any of her past memory of infections to her unborn child. This includes antibodies (I call them darts in my immune story) against whatever you’ve seen so far in your life, but also something you might have recently met.

Like a COVID-19 vaccine.

To your body the vaccine will pretty much look like the real virus. Or at least your cells won’t know the difference. Days after you received the vaccine your immune cells will make antibodies (and do tons of other stuff) and you, the mother-to-be will pass on your own immune protection to your unborn child. It is called passive immunity, because the baby itself doesn’t contribute much herself or himself.

She or he just gets it from you.

A gift.

And it will protect him or her for a couple of months. Obviously, it depends on how long you will make antibodies and how long they ‘last’, so to speak.

Another way to achieve passive immune protection of your newborn is through breastfeeding.

If you’re breastfeeding and consider getting the vaccine, great!

The moment you make antibodies, you can also pass these on to your child through your breastmilk. This as well gives your newborn a good start in life and protects him or her for the first crucial couple of months.

So, I guess I could have waited until my baby was born and I would breastfeed her. But then again, it’s not a given that one can breastfeed. It does not always work and there are multiple reasons why not every baby is breastfed.

I simply decided I want to vaccinate now. Not knowing what will happen in the future, I can only choose for the best option at this moment.

Also, the developments around the delta variant (the one initially spotted in India) of the corona virus are worrying me a bit. I envision that we will get another rise of infections in the fall or winter this year and I simply want my child to have a general protection by that time. So far scientific studies seem to suggest that once you get infected with the delta variant and you have been vaccinated, your risk of developing serious complications is smaller than if you wouldn’t have been vaccinated at all.

But after all, getting vaccinated, if and when is a very personal decision.

Are you also pregnant? What do you decide to do and why? I'd love to hear from you.

If you're not, what do you think about getting vaccinated? Pregnant or not?

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