A new study has revealed that most women who catch COVID-19 during pregnancy pass on protective antibodies to their unborn babies.
The research results were announced at the European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) in the Portuguese capital Lisbon, which took place between 23rd and 26th April.
Antibodies are transferred from mums to their infants during the last three months of pregnancy, providing the child with protection against particular infections or illnesses when they are born.
However, few studies have taken place concerning Covid antibodies being transferred from mothers to their babies in either vaccinated or unvaccinated groups.
The new study focussed on pregnant women who contracted the novel coronavirus before the new vaccines were widely rolled out.
Dr Liliana Gabrielli and the research team at the Sant’Orsola-Malpighi Polyclinic, University of Bologna, studied data of over 4,000 women who gave birth in the Italian city of Bologna between 1st July 2020 and 31st March 2021.
The mothers all underwent PCR tests to check for Covid-19 infection before blood samples were taken to test for antibodies, providing evidence of past infection.
The newborns were also tested for Covid, and infants whose mother tested positive for antibodies were also checked for antibodies.
Of the group, 136 women (3.4 percent) had Covid antibodies in their blood while 26 percent of these mothers had both IgG (older infection) and IgM (more recent infection) antibodies.
In the findings, 74 percent of the women had IgG antibodies but tested negative for more recent or current infections.
Blood samples from 73 babies born to mums with Covid antibodies showed that none had IgM antibodies, but this was to be expected as IgM does not cross the placenta.
Eleven of the 73 infants were IgG and IgM negative while the other 62 were IgG positive.
Meanwhile, all 73 tots had negative PCR tests shortly after birth, indicating that they did not have the novel coronavirus and antibodies were passed on to them by their mother.
Dr Gabrielli said: “This study of pregnant women and their newborns, which was carried out in the pre-vaccination era, found that 3.4 percent of the women had COVID-19 during pregnancy.
“Most of these women passed antibodies to their babies. However, the protection provided by these antibodies will gradually decrease over time and disappear within 100 days of birth in most cases.
“Other studies are looking at how well antibodies produced by vaccination pass from mother to child.”