Pregnant women with COVID-19 during the third trimester are unlikely to pass the virus to their newborns, according to a research conducted in the United States of America.
The study, led by Dr Andrea Edlow of the Harvard Medical School was published in the journal, JAMA Network Open.
According to the publication, the study followed 127 pregnant women admitted to Boston hospitals during the spring of 2020.
Among the 64 pregnant women who contracted SARS-CoV-2, the virus that causes COVID-19, no newborns tested positive, the study said.
The researchers examined the occurrence of SARS-CoV-2 infection in the third trimester of pregnancy.
They evaluated the levels of virus in respiratory, blood and placental tissue samples and the development of maternal antibodies.
The study looked at how well those antibodies passed through the placenta to the fetus (an indicator of potential immune protection from the mother) and examined placental tissue.
According to the publication, the results reported are limited to women in the third trimester because data on women infected during the first and second trimesters were still being collected and evaluated.
“Among those (64) who tested positive for SARS-CoV-2 in the study, 36 per cent were asymptomatic, 34 per cent had mild disease, 11 per cent had moderate disease, 16 per cent had severe disease, and three per cent had critical disease.
“The study included, as comparators, 63 pregnant women who tested negative for SARS-CoV-2 and 11 reproductive-age women with COVID-19 who were not pregnant.
“The team found that pregnant women who were positive for SARS-COV-2 had detectable levels of virus in respiratory fluids like saliva, nasal and throat secretions, but no virus in the bloodstream or the placenta,” the publication stated.
Finally, the study demonstrated that while the placentas of women infected with COVID-19 were similar to those of uninfected women, their findings showed that COVID-19 infection increased a mother’s risk of reduced blood from to the placenta, with the effects being elevated in those with more severe COVID-19 infections.
In addition, researchers found that the two major molecules used by COVID-19 were present placentas of women infected with the virus, however, these molecules were rarely found expressed in the same location, suggesting why the placenta is rarely affected by the virus.
The study’s findings will likely improve care for mothers testing positive for COVID-19, as well as paving the way for future researchers that may facilitate the development of new vaccination strategies for pregnant women.