The SARS-CoV-2 virus, which causes COVID-19, can be transmitted from mother to baby before, during and after childbirth, but such occurrences are rare, according to a study published in The BMJ. The researchers found that less than two per cent of babies born to mothers with SARS-CoV-2 infection also test positive for the virus.

However, they are more likely to test positive when the women have severe COVID-19 or were diagnosed after childbirth. The team led by researchers at the University of Birmingham in the UK also found that vaginal births and breast feeding do not increase the likelihood of babies testing positive for SARS-CoV-2 when their mothers have the infection.

The study examined data from around the globe relating to more than 14,000 babies born to mothers with COVID-19. Overall, 1.8 per cent of the 14,271 babies born to mothers with SARS-CoV-2 infection tested positive for the virus using PCR tests, the researchers said. "Ours is the first study to use the World Health Organization's stringent methods to show that it is possible for the virus to be spread from the mother to baby while in the womb, during childbirth, and after delivery," said study lead Shakila Thangaratinam, a professor at the University of Birmingham.

“However, parents and healthcare professionals can be reassured that only a very small proportion of babies born to mothers with SARS-CoV-2 test positive. This implies that the risks of infection to such babies are rare," Thangaratinam said. The researchers noted that mothers should also be reassured about the low risk of viral transmission through vaginal birth, skin-to-skin contact and breastfeeding, all of which should be encouraged. Healthcare professionals and policy makers need to be aware of the expected burden of SARS-CoV-2 positivity in babies, they said.

The risk of infection at any time during pregnancy and delivery highlights the need for appropriate measures to reduce risk of viral transmission in the postnatal period, according to the researchers. The team recommends that since babies born to mothers with severe SARS-CoV-2 are more likely to test positive, they will need to be tested after birth and monitored closely. Vaccination during pregnancy should be further encouraged to prevent infection and severe disease in mothers, the researchers added.

With PTI Inputs