Two recently published studies highlight the potential impact of SARS-CoV-2 infection during pregnancy. A study found that placental abnormalities and fetal bleeding may be linked to COVID during pregnancy. Researchers are now monitoring children exposed to the virus prenatally to see if there are long-term neurodevelopmental effects.
Before the emergence of SARS-CoV-2 in 2020, there was significant research investigating the effects of viral infections during pregnancy. It is well understood that the immunosuppressive nature of pregnancy makes viral infections dangerous and increases the risk of maternal morbidity, stillbirth or preterm birth.
However, even mild infections in pregnant women can have long-term developmental effects on the growing fetus. Although it is often a mild illness, infection during pregnancy can lead to birth defects and neurological deficits in children.
Influenza infection during pregnancy has also been well studied. Several long-term studies have looked back at children born during the 1918 influenza pandemic and found that in utero exposure to influenza varied during adulthood, from increased incidence of cardiovascular disease to reduced levels of education. suggested that it could have harmful effects.
Recent studies have linked maternal influenza infection to increased rates of autism and schizophrenia. However, it is unclear exactly how a child’s neurodevelopment may be affected by viral exposure during pregnancy. It has been suggested to be an important factor that inhibits development. Other studies point to inflammatory molecules that cause changes in fetal brain development.
Importantly, these long-term effects on neurodevelopment have been detected after mild viral infections during pregnancy. It is an infection that does not give
Given the existing body of evidence, therefore, researchers have closely studied the effects of COVID during pregnancy. I’m starting to get some insight into what kind of impact it’s making.
A new study led by researchers at King’s College London looked at more than 600 samples of fetal brain tissue collected from elective abortions between 2020 and 2022.
Cortical hemorrhages were found in approximately 5% of the samples analyzed, and the researchers also detected the presence of SARS-CoV-2 in all of those samples. The study’s principal investigator, Katie Long, said it was unusual to find so many hemorrhagic brain tissue samples among randomly collected samples.
“Bleeding can happen in the developing brain, but it’s very unusual to have so many bleeds in a 21-month period,” Long said. It is of utmost importance now to follow up these children to see if there are any long-term neurodevelopmental effects.”
Of greatest concern to researchers is the observation that most of the hemorrhages detected were found in fetal brain tissue during the late first and early second trimesters of pregnancy. The researchers say it is unclear whether these abnormalities resolved spontaneously during the course of a healthy pregnancy, but maternal immune activation during this critical early stage of neurodevelopment may be a long-term problem. can cause
“……Majority [of the haemorrhages detected] This is a key window in human fetal brain development when endothelial tight junctions increase to form the blood-brain barrier,” the researchers wrote. , or can be resolved with minimal consequences. An immune cell response may have a positive outcome, resulting in some resolution of these bleedings. However, maternal immune activation can have many long-term effects on neurodevelopment.”
Another newly published study by a team of Austrian researchers uses MRI to study the effects of SARS-CoV-2 infection on the placenta and fetus. This is the first study to use prenatal MRI to study placental structure and fetal organs in pregnant women who have recovered from COVID infection.
In this study, MRI studies were performed on 38 pregnant women with confirmed SARS-CoV-2 infection. Scans were performed, on average, approximately 80 days after each participant’s first positive PCR test. Each COVID-positive participant was matched with an uninfected control carrying a child of similar gestational age.
Findings revealed that participants with SARS-CoV-2 infection showed significantly more placental abnormalities compared with controls. These included changes in the shape and thickness of placental and vascular lesions.
This study highlights the need for pregnant women to be vaccinated against COVID-19, so complications for both mother and baby can be avoided.
The study also revealed that the pleomicron variant of the virus causes greater placental damage than the currently circulating omicron variant. The researchers suggest that this difference may be due to Omicron being less severe compared to previous variants, but that increased vaccination coverage has weakened the virus’ impact. There is a possibility.
“Such variable occurrence of placental lesions with different viral variants may be due to the low virulence of the omicron variants and higher vaccination coverage as the pandemic progressed,” the researchers said. writes, “Our results show that two unvaccinated pregnant women infected with SARS-CoV-2-Omicron developed placenta spheroids, whereas out of six women vaccinated three times showed that only one of the patients developed a placenta.”
Of course, these two studies have the same caveats faced by many of this type of investigation. They are unable to determine causality and do not shed light on the long-term effects of the cited anomalies.
It will take years for researchers to understand the potential link between in utero exposure to SARS-CoV-2 and neurodevelopmental disorders. A study published in mid-2022 looked at hundreds of 12-month-old children born to a mother who faced her COVID infection during pregnancy in the first wave of the pandemic, revealing some of the first clues. provided.
These findings revealed a higher rate of developmental deficits related to motor function or speech and language compared to unaffected controls. However, many of these babies were born prematurely, so it is unclear whether the viral infection directly caused neurodevelopmental problems, or whether COVID simply caused the premature birth, which itself is associated with developmental delays. Unknown.
Other researchers commenting on the 2022 study suggest that it is too early to diagnose developmental disorders in children. suggesting that it is difficult to believe that children as young as 12 months of age are effectively diagnosed with developmental disorders.
“As an expert in children’s speech and language disorders, it’s hard to understand how these conditions can be diagnosed in such young children, because it’s not abnormal if the child doesn’t say a word at all. “Obviously, pregnant women should do their best to avoid COVID, but if they do get it, they can have neurodevelopmental problems evident in their infants within the first year of life,” Dixon said. is more likely not to occur.
Lucilla Poston, a materials and fetal health researcher at King’s College London, said it’s certainly possible that COVID during pregnancy could affect the developing fetal brain. While more research over the years will inevitably yield insights into the link, Poston said it’s clear that vaccination against COVID during pregnancy is important to reduce the severity of the infection. I said there is.
“We know that severe viral infections can affect the fetal brain, but this important study suggests that this can occur in pregnancies affected by COVID infection. It’s the first one,” Poston commented on the King’s College fetal tissue findings. “Whatever the cause, whether it’s a direct effect of the virus or an indirect result of maternal infection, this study suggests that pregnant women can be vaccinated against COVID-19 to avoid complications for both mother and baby. It emphasizes the need to
An ongoing study called BIBS (Brain Imaging in Babies Study) is underway at King’s College London. Track children born to mothers who test positive for COVID-19 during pregnancy. Using MRI images and behavioral assessments, researchers will examine her brain development through age four.
A study of fetal tissue was published in a journal brainplacental MRI study published Lancet Regional Health.
Source: King’s College London, Medical University of Vienna
