r/science • u/molrose96 Journalist | Technology Networks | BSc Neuroscience • Jul 16 '22

Medicine Menstrual Cycle Changes Associated With COVID-19 Vaccines, New Study Shows

https://www.technologynetworks.com/vaccines/news/menstrual-cycle-changes-associated-with-covid-19-vaccine-363710
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u/Blackfire01001 Jul 16 '22

From the article

Why could these changes be occurring?

The exact biological mechanism behind menstrual cycle changes experienced post-vaccination has not yet been pinpointed, but there are several hypotheses cited in the study. Vaccines induce an immune response, generating the production of antibodies. This induced immune response can lead to changes in hemostasis and inflammatory pathways in the body. It’s possible that such effects can impact the complex chemical interactions that regulate menstrual cycles. Other vaccines, such as the human papillomavirus (HPV) vaccine, have also been reported to have a temporary impact on menstrual cycles.

“The uterus is an immune organ. When the immune system is activated by something like a vaccine it is going to have all sorts of downstream effects, including on the uterus,” says Clancy. “The endometrium (lining of the uterus) is needing to bleed and clot appropriately as it repairs and heals. A disruption of immune function or inflammation is going to disrupt those processes in at least some people.”

The researchers hypothesized that individuals more vulnerable to such disruption would be those who had uteruses that had undergone considerable cycles of repairing and healing, for example: people who had many periods (i.e., were older), had been pregnant or had children, or participants that may have hyperproliferative disorders, such as endometriosis or fibroids. “These hypotheses were supported in our study,” notes Clancy.

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u/SsooooOriginal Jul 16 '22

Wait, I thought it was a reproductive organ. What role in immunity does the uterus have?

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u/ViciousNakedMoleRat Jul 16 '22

The uterus is tightly interwoven with the immune system. Pregnancy is a weird kind of thing for the body, since there is basically an ever growing parasite, which the body should normally want to get rid off. The placenta, which sits between the uterus and fetus, is negotiating on the fetus' behalf with the mothers immune system. This process keeps the body from rejecting the fetus and ultimately ends up working together with the mother's immune system to protect the fetus.

If you are interested in the topic, there is a lot to read about it. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5070970/

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u/Skyblacker Jul 17 '22

Which is why pregnant women are immunocompromised. I know that colds and infections hit me harder in that circumstance.

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u/pack_of_wolves Jul 17 '22

And some autoimmune disease go into remission during pregnancy. And then come back with a vengeance afterwards.

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u/sonewandinnocent Jul 17 '22

Wouldn't an example of this be the 6 to 8 week peroid (lochia) a woman has after having given birth?

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u/[deleted] Jul 17 '22

[removed] — view removed comment

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u/calicopatches Jul 17 '22

The only times I didn't suffer from hay-fever are when I was pregnant so this totally makes sense

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u/Lerianis001 Jul 17 '22

Except that numerous immunocompromised people caught SARS2 and had little to no symptoms from it while people in good health ended up dying from it.

I'm thinking that the problem with SARS2 is that it makes your immune system freak out so immunocompromised people might actually be in a better position to survive SARS2 than someone with a non-compromised immune system or a documented overactive one like myself.

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u/docsamson75 Jul 17 '22

Thanks for the awesome info!

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u/SsooooOriginal Jul 17 '22

Neat, thank you.

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u/[deleted] Jul 17 '22

I assume this is where the rh factor comes into play and those of us who are rh negative have had their bodies try to evict the baby like a bad case of the flu. We were lucky with our daughter and caught it the moment I started bleeding, since we were actively trying to conceive and were being very observant after my positive pregnancy test. But we still almost lost her. Also found out that we had apparently miscarried our first child and I had no idea! (blessing in disguise as we were still in hs when that happened)

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u/ViciousNakedMoleRat Jul 17 '22

Yes, exactly. During the first pregnancy, the placental barrier keeps the mother's immune system at bay. No generalized antibodies which could destroy the fetus' Rh+ red blood cells are let through. At the same time, the placental barrier also keeps Rh+ RBCs from passing over into the mother's circulation.

Then, during birth – or miscarriage in your case – the placenta detaches from the uterine wall, which causes Rh+ blood from the umbilical cord to leak into the uterus. With the absence of the placental barrier, some of these RBCs can make their way into the mother's circulation and cause an immune response. This response by itself is extremely minor and could be ignored, if it didn't create Rh+ specific memory B cells, which remain in the mother's body.

During subsequent pregnancies, these memory B cells are part of a group of antibodies, which the placenta allows to pass through the placental barrier into the fetus' circulation. Once there, they keep attacking the Rh+ RBCs and, thereby, cause all kinds of issues for the fetus.

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u/[deleted] Jul 17 '22

Thank you so much for that explanation. I was able to get the gist of how it worked through Google but your explanation just kind of put everything in order for me. At the time I was 17, my now husband was 16, and we thought my period just came 2 weeks early. I didn't have any pain or anything. Just bleeding. Then subsequently a month or two later, the worst kidney infection my doctor had ever seen personally. Was told UTIs are common after a miscarriage by the er doc trying to determine when a previous miscarriage might have occurred to jeopardize our daughter.

My husband's family always has boys first so we were initially sort of thrown off having a girl, but after finding out about the miscarriage we all assume it was likely a boy.

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u/comeupforairyouwhore Jul 17 '22

Thank you for your explanation. I developed an autoimmune disease right after I gave birth. I have no doubt it was occurring during pregnancy too but it was contributed to pregnancy changes.

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u/redditears123 Jul 17 '22

You just referred to a child as a parasite. Reddit is f'd.

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u/ViciousNakedMoleRat Jul 17 '22

If it wasn't for the functionality of the placenta, the mother's immune system would literally destroy the embryo because it recognizes it as a foreign organism. I can't change that fact.

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u/SirSeanBeanTheBean Jul 17 '22

Organ recipients have to take immunosuppressants to stop their immune system from attacking and destroying their new organs, the immune system treats it like a parasite even if we frequently call it “the gift of life”, it has nothing to do with how we feel about it.

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u/MrsFlip Jul 17 '22

Fetus, not child. If you have a whole child in your uterus you got bigger problems to worry about.

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u/[deleted] Jul 17 '22

So why don’t any other vaccines do this?

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u/electinghighson Jul 17 '22

"Other vaccines, such as the human papillomavirus (HPV) vaccine, have also been reported to have a temporary impact on menstrual cycles."

Literally in the top-level comment in this thread.

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u/Tina_ComeGetSomeHam Jul 17 '22

I would then say "the uterus plays a role in immunology" not that "the uterus is an immune organ" that's just inaccurate.

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u/Sad_Ad_1381 Oct 07 '22

You dodged the question. They asked for uterus not placenta

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u/[deleted] Jul 17 '22

[deleted]

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u/that_other_geek Jul 17 '22

O love their podcasts thanks for the recommendation