Science and Technology Daily (Reporter Zhang Mengran) According to a recent case study published by the British "Nature·Communications" magazine, a team of French scientists reported relevant evidence that a mother who tested positive for the new coronavirus may have transmitted the virus to the placenta Infants, and the new coronavirus may also actively replicate in placental cells.
Past studies have shown that neocoronavirus transmission may occur during the perinatal period (before and after birth), but it is not clear whether it occurs through the placenta (a cervical route) or because of environmental exposure.
Daniel de Luca, a scientist at Antoine Becquerel Hospital in France and University Hospital de Saclay in Paris, and his collaborators showed the results of a case study this time, showing that the new coronavirus may be transmitted through the placenta. In this case, a pregnant woman in her twenties was admitted to hospital with fever and severe cough. Blood tests, nasopharyngeal swabs and vaginal swabs confirmed the presence of the "E" and "S" genes of the new coronavirus (encoding the viral envelope and spike protein, respectively). The nasopharyngeal swab and rectal swab of the baby were collected 1 hour after caesarean section, and then collected again after 3 days and 18 days, and the "E" and "S" genes were detected. Newborn blood and bronchoalveolar perfusion tests were also positive.
The research team observed that the baby had neurological symptoms associated with the new coronavirus infection, which is similar to the symptoms reported by adult patients. Neuroimaging analysis showed that the white matter was damaged, and the research team speculated that it may be caused by inflammation of the blood vessels induced by the new coronavirus infection. No other viral or bacterial infections were found, and all other neonatal diseases that might cause these clinical symptoms were excluded.
Eventually, the mother and her child were discharged.
The researchers also found that the viral load in the placenta is higher than the viral load in amniotic fluid and maternal blood, which means that the new coronavirus may actively replicate in the placental cells and cause neonatal viremia. This is consistent with the level of inflammation found in histological examination of the placenta. They concluded that by confirming the presence of new coronavirus in placental tissue, maternal blood and neonatal blood, they believed that mother-to-child transmission was most likely to occur through the placenta.