- Pregnant women in their third trimester infected with Covid-19 are unlikely to transmit the disease to their newborns
- Experts found that there was a low transfer of antibodies from mother to foetus
- Similar first and second-trimester studies are still in progress
Pregnant women who have tested positive for SARS-CoV-2, the virus that causes Covid-19, and are in their third trimester, are unlikely to pass the virus to their newborn babies, a new study has found.
The research published in JAMA Network Open examined 127 pregnant women who were admitted to hospital in Boston, USA. Of these women, 64 tested positive for Covid-19, while in all of their newborns the tests were negative.
"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 Dr Diana Bianchi of the National Institute of Child Health and Human Development in a press release.
Low transfer of antibodies in mothers-to-be to foetus
Researchers tested for the virus in the final trimester of the pregnant women in the study. They searched for the virus in the respiratory system, blood and placental tissue samples. They also observed the development of maternal antibodies, and how well those antibodies passed through the placenta to the foetus, and examined placental tissue.
Experts found that pregnant women who tested positive for Covid-19 had detectable levels of virus in respiratory fluids like saliva, nasal and throat secretions, but no virus in the bloodstream or the placenta.
They also found that there was low transfer of antibodies in mothers-to-be to the foetus, regardless of the severity of the symptoms the mother experienced, or the number or severity of the comorbidities she had.
The above findings exclusively focused on third-trimester pregnancies – as first- and second-trimester studies are still in progress.