An anonymous reader quotes a report from The New York Times: Researchers on Tuesday [reported in the journal Nature Communications] strong evidence that the coronavirus can be transmitted from a pregnant woman to a fetus. A baby born in a Paris hospital in March to a mother with Covid-19 tested positive for the virus and developed symptoms of inflammation in his brain, said Dr. Daniele De Luca, who led the research team and is chief of the division of pediatrics and neonatal critical care at Paris-Saclay University Hospitals. The baby, now more than 3 months old, recovered without treatment and is “very much improved, almost clinically normal,” Dr. De Luca said, adding that the mother, who needed oxygen during the delivery, is healthy.
Dr. De Luca said the virus appeared to have been transmitted through the placenta of the 23-year-old mother. The testing indicated that “the virus reaches the placenta and replicates there,” Dr. De Luca said. It can then be transmitted to a fetus, which “can get infected and have symptoms similar to adult Covid-19 patients.” [Dr. Yoel Sadovsky, executive director of Magee-Womens Research Institute at the University of Pittsburgh] said, it is important to note that cases of possible coronavirus transmission in utero appear to be extremely rare. With other viruses, including Zika and rubella, placental infection and transmission is much more common, he said. With the coronavirus, he said, “we are trying to understand the opposite — what underlies the relative protection of the fetus and the placenta?”
Another study published on Tuesday in eLife, an online research journal, may help answer that question. It found that while cells in the placenta had many of the receptor proteins that allow viruses to propagate, there was evidence of only “negligible” amounts of a key cell surface receptor and an enzyme that are known to be involved in allowing the coronavirus to enter cells and replicate. The study was led by Dr. Robert Romero, chief of the perinatology research branch at the Eunice Kennedy Shriver National Institute of Child Health and Human Development.