The risk of miscarriage after a corona infection increases sharply because the virus probably affects the placenta
Experts agree: a corona infection during pregnancy significantly increases the risk of miscarriage and other serious complications.
US pathologists from Boston have now succeeded for the first time in detecting the delta mutant of the coronavirus in the placenta of three pregnant women. The women suffered miscarriages. Whether the unborn children were also infected remains unclear because the researchers were unable to autopsy the fetuses.
Meanwhile, a study from Scotland shows that unvaccinated pregnant women are especially at risk. So 98 percent of pregnant infected women who ended up in intensive care were unvaccinated.
It became clear quite early in the pandemic that Corona infection during pregnancy increases the risk of miscarriage and other complications. With the emergence of the delta mutation, severe cases among pregnant women continued to accumulate. In November, a study by the U.S. Centers for Disease Control and Prevention (CDC) produced the worrying result that the risk of stillbirth increases fourfold after corona infection.
However, it remained unclear for a long time whether the complication was a consequence of the mother’s infection or whether the placenta and the unborn child itself had been infected with Corona. U.S. pathologists from Boston have now been able to detect the coronavirus in the placenta of three pregnant women, as reported in the "arzteblatt" journal. The study was recently published in the Journal of Infectious Diseases.
Andrea Edlow of Massachusetts General Hospital in Boston and her research team report in the study that each of the pregnancies studied ended prematurely within 14 days of the onset of the disease: Two women suffered miscarriages, and the third woman was born at 31. Delivered at one week of pregnancy. The newborn had hyperacidity of the blood and suffered from respiratory distress. However, the doctors attributed this to the early birth. Because Covid-19 could not be detected in the child.
But: In all three women, the placenta had inflammatory changes. And in trophoblasts, the cell layer responsible for nourishing the embryo, the researchers detected Sars-CoV-2 RNA. PCR test on placental tissue was also positive. Sequencing confirmed the suspicion that the women had been infected with the delta variant. The research team also found the virus in the pregnant woman’s blood samples.
Were the unborn children infected?
The pathologists were unable to determine whether the babies had also been infected with the virus because the parents did not want the deceased fetuses to be autopsied and tested for Corona. It remains unclear whether the unborn children were actually infected.
Still, the new findings are troubling. Until now, experts had assumed that coronavirus could not cross the placental barrier because they observed an increase in preterm births but no increase in fetal malformations. In an earlier study of 64 cases, the Boston team was also unable to find SARS-CoV-2 in the blood of the mothers or in the placentas. With the delta variant, however, this had changed. Edlow believes mutant poses greater risk to pregnancy than earlier variants.
Increased risk for the unvaccinated
What is clear is that Corona infection during pregnancy can be lightning dangerous for both mother and child – especially for unvaccinated individuals. This is again shown by a study from Scotland, which was recently published in the journal Nature Medicine. The research team, led by Sarah Stock of the University of Edinburgh, had access to all pregnancies in Scotland, which they were able to match to the vaccination registry.
As part of the study, researchers collected data from women who became pregnant between March 2020 and October 2021. The findings are clear: 77 percent of those infected with Covid-19 were unvaccinated. One in five non-immunized pregnant women had a severe covid-19 course and required inpatient treatment. In contrast, among those with vaccine breakthroughs, only one in twenty required hospitalization. Nearly all pregnant infected patients who ended up in intensive care – 98 percent – were unvaccinated. One woman died.
Misconceptions and misinformation keep some pregnant women from getting vaccinated against the virus. But experts have long debunked false rumors – such as an increased risk of premature birth after vaccination – and supported the notion that unvaccinated pregnant women run a much higher risk of serious complications, as Business Insider previously reported.
In Germany, pregnant women are officially considered a risk group for severe covid 19 disease. The Standing Commission on Vaccination (STIKO) therefore appeals to women who wish to have children to be vaccinated urgently in order "to be optimally protected against this disease from the time of conception during pregnancy in the event of a future pregnancy".
This article was last published on 21. January 2022 updated. He was born on 18. January 2022 published.