There are plenty of reasons to worry about COVID-19 already, but there’s one more to add to the list: There’s some evidence that the virus resides in fetal brain tissue in cases where pregnant people pass the infection on to their children .
So it’s not just the effects of the disease on our bodies that are of concern, but also the effects on the bodies of babies who are still pregnant – something that scientists have already urgently looked into.
The team studied 661 human fetal tissue samples collected between July 2020 and April 2022, and observed bleeding in 26 of them. COVID-19 was present in all tissue samples with evidence of bleeding.
All samples were collected from electively terminated pregnancies.
“While bleeding does occasionally occur in developing brains, it is extremely unusual for there to be so many cases within a 21-month period,” says neurobiologist Katie Long of King’s College London in the UK.
“It is now paramount that we follow up on children who have been prenatally exposed to COVID-19 so that we can determine whether there are any long-term neurological effects.”
Researchers highlighted signs of reduced blood vessel integrity and an increase in immune cells infiltrating the brain as being linked to tissue damage. This may be a direct result of the COVID-19 infection or an indirect result of the mother’s immune response.
Although the coronavirus was only confirmed in fetal tissues, it can be safely assumed that the infections were passed on through infection in their mothers. Whether the bleeding was a direct result of the mother’s COVID or fetal infection — or whether some unknown factor is involved in the relationship — is not clear. But the link is strong enough to be a concern.
In addition, most of the samples with evidence of bleeding were from the late first and early second trimester of pregnancy, suggesting that the brain of the fetus may be affected in the earliest stages of its development. We already know that this is a crucial time for the developing brain as it puts up barriers to defend itself.
“We know that a severe viral infection can affect the fetal brain, but this important study is the first to suggest that this may occur in pregnancies affected by COVID infection,” says physiologist Lucilla Poston of King’s College London. Poston was not involved in the investigation.
“Whatever the cause, a direct effect of the virus or an indirect result of maternal infection, this study highlights the need for pregnant women to be vaccinated against COVID-19 to prevent complications for both mother and baby.”
Traces of SARS-CoV-2 were also detected in tissue samples from the placenta, amniotic fluid and umbilical cord, suggesting that the presence of COVID-19 could potentially cause further complications.
Viral infections in mothers are regularly associated with neurological damage in children; the Zika virus is one of the more high-profile cases in recent years, demonstrating how significant these effects can be.
We have previous studies linking fetal health problems to cases of COVID-19 in pregnant mothers, but so far the amount of data on this topic is relatively small – something that scientists will try to change in the future.
“Our findings suggest that there is a link between the early development of human fetal brain tissue and vulnerability to infection from COVID-19,” said neurobiologist Marco Massimo of King’s College London.
The research has been published in Brain.