Washington,  Pregnant women who are infected with SARS-CoV-2, the virus that causes Covid-19, during the third trimester are unlikely to pass the infection to their newborns, according to a new study.

The study, funded by the US National Institutes of Health, followed 127 pregnant women who were admitted to Boston hospitals during the spring of 2020.

Among the 64 pregnant women who tested positive for SARS-CoV-2, no newborns tested positive for the virus, reports Xinhua news agency.

"This study provides some reassurance that SARS-CoV-2 infections during the third trimester are unlikely to pass through the placenta to the foetus, but more research needs to be done to confirm this finding," said Diana Bianchi, director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development.

The results reported are limited to women in the third trimester because data on women infected during the first and second trimesters are still being collected and evaluated, according to the study, published in the journal JAMA Network Open.

The researchers suggest their findings could help improve the care of pregnant women with Covid-19 and of their newborns, as well as provide information to assist in the development of new strategies for vaccinating pregnant women.