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Can a #COVID19 infection during pregnancy lead to infection of the fetus?
A mix of suspicious case reports and scientifically inaccurate articles have muddled this area.
Actually, SARS-CoV-2 doesn’t even need to infect the fetus to harm neurodevelopment.
A thread…..1/10
A mix of suspicious case reports and scientifically inaccurate articles have muddled this area.
Actually, SARS-CoV-2 doesn’t even need to infect the fetus to harm neurodevelopment.
A thread…..1/10
One study was titled, “Vertical transmission of COVID19…” and based on finding SARS-CoV-2 RNA on the “fetal side” of the placenta.
No, no, no.
https://marlin-prod.literatumonline.com/pb-assets/Health%20Advance/journals/ymob/AJOGMF-20-1112.pdf
2/10
No, no, no.
https://marlin-prod.literatumonline.com/pb-assets/Health%20Advance/journals/ymob/AJOGMF-20-1112.pdf
2/10
If we are talking vertical transmission, the "fetal" side is within the chorionic villous and ideally inside the fetal blood vessels.
The authors showed staining of syncytiotrophoblasts - the outer covering of the villous, but not staining inside the villous core.
3/10
The authors showed staining of syncytiotrophoblasts - the outer covering of the villous, but not staining inside the villous core.
3/10
My guess is that syncytiotrophoblasts infected by SARS-CoV-2 mounted an interferon response, which shut the virus down right then and there.
This is what these cells were born to do.
A nice paper by @scienceCC showing how it works with #Zika.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4866896/
4/10
This is what these cells were born to do.
A nice paper by @scienceCC showing how it works with #Zika.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4866896/
4/10
Another paper came out suggesting that SARS-CoV-2 could be visualized in the placenta using transmission electron microscopy.
Gigantic measurements bars (500 nm) on the images so nearly impossible to estimate the exact virion size.
Big problem.
https://www.ajog.org/article/S0002-9378(20)30549-4/pdf
5/10
Gigantic measurements bars (500 nm) on the images so nearly impossible to estimate the exact virion size.
Big problem.
https://www.ajog.org/article/S0002-9378(20)30549-4/pdf
5/10
SARS-CoV-2 is a BIG virus – the size of its cousin SARS-CoV-1 is ~100-130 nm.
I would expect the SARS-CoV-2 virion to take up ~1/5 to 1/4 of their measurement bar (or more).
Only their image #3 is big enough – but one ”virion” does not make the case.
6/10
I would expect the SARS-CoV-2 virion to take up ~1/5 to 1/4 of their measurement bar (or more).
Only their image #3 is big enough – but one ”virion” does not make the case.
6/10
Here are some nice pictures of SARS-CoV-2 – many, many virions within an intracytoplasmic organelle – maybe smooth endoplasmic reticulum (ER).
Viruses use the ER as a membrane factory to replicate.
Very pretty.
https://www.forbes.com/sites/victoriaforster/2020/04/18/what-does-coronavirus-look-like-cdc-releases-images-from-first-american-covid-19-patient/#fb048aa3577a
7/10
Viruses use the ER as a membrane factory to replicate.
Very pretty.
https://www.forbes.com/sites/victoriaforster/2020/04/18/what-does-coronavirus-look-like-cdc-releases-images-from-first-american-covid-19-patient/#fb048aa3577a
7/10
Years ago, I called CDC to ask if “Zika virus” TEM images were correct from a microcephaly case report.
No, they said – that isn’t virus. THIS is virus (sent me a pic).
Since then, I have hunted for Zika virions in KNOWN infected tissues -- in vain!
Viruses are ELUSIVE.
8/10
No, they said – that isn’t virus. THIS is virus (sent me a pic).
Since then, I have hunted for Zika virions in KNOWN infected tissues -- in vain!
Viruses are ELUSIVE.
8/10
More convincing is detection of IgM in a newborn delivered by C-section.
Mother wore an N95 mask and did not hold the infant.
IgM is not passed from mother to fetus due to its large size, thus, good evidence of vertical transmission.
https://jamanetwork.com/journals/jama/fullarticle/2763853
9/10
Mother wore an N95 mask and did not hold the infant.
IgM is not passed from mother to fetus due to its large size, thus, good evidence of vertical transmission.
https://jamanetwork.com/journals/jama/fullarticle/2763853
9/10
SARS-CoV-2 does not need to invade the placenta and the fetus to cause problems.
The mere act of causing illness in the pregnant woman and the ensuing inflammation – even if mild – is enough supports this.
https://www.ncbi.nlm.nih.gov/pubmed/30840048
https://www.ncbi.nlm.nih.gov/pubmed/31207234
10/10
The mere act of causing illness in the pregnant woman and the ensuing inflammation – even if mild – is enough supports this.
https://www.ncbi.nlm.nih.gov/pubmed/30840048
https://www.ncbi.nlm.nih.gov/pubmed/31207234
10/10
The focus should not be on whether the virus invades the placenta....it might in certain cases if the placental interferon response is impaired....
More concerning is the silent injury that a maternal infection can do the developing fetal brain, which may not manifest for years.
More concerning is the silent injury that a maternal infection can do the developing fetal brain, which may not manifest for years.
