Pregnant women infected with the new coronavirus may be able to pass it to their unborn children, doctors at the Wuhan Children Hospital said on Wednesday, according to state broadcaster CCTV.

The doctors said it was possible after an infected coronavirus patient gave birth to a baby on February 2. The newborn was given a test 30 hours later and confirmed to have the virus, the doctors said.

Wuhan city is the epicentre of the outbreak that has since spread across China and overseas. In mainland China, it has killed 490 people and 24,324 infection cases have been confirmed.

The newborn has stable vital signs and no fever or cough, but was experiencing shortness of breath, the doctors said. Chest X-rays showed signs of infection and there were some abnormalities in liver functions.

"This reminds us to pay attention to mother-to-child being a possible route of coronavirus transmission," said the chief physician of Wuhan Children Hospital's neonatal medicine department, Zeng Lingkong.

The hospital also disclosed details of a second case involving an infant who was born healthy on January 13. The baby's nanny was later diagnosed with the virus and the mother days later. The baby started showing symptoms on January 29.

"Whether it was the baby's nanny who passed the virus to the mother who passed it to the baby, we cannot be sure at the moment. But we can confirm that the baby was in close contact with patients infected with the new coronavirus, which says newborns can also be infected," Zeng said.

However, he added that none of the infected infants were in critical condition.