An Italian woman has given birth to quintuplets, but the mother and the babies are in a serious condition, doctors at a hospital in the Sicilian city of Messina said.

The quintuplets' birth on Thursday was kept secret until now at the request of the parents, they said.

The babies, four girls and a boy, were born two months premature. The smallest weighed 550g while the biggest weighed 1.2kg. All five are in incubators.

"The quintuplets are 28 weeks and two days old and if a premature birth is a difficult situation when there is one child, imagine when there are five of them," Dr Eloisa Gitto said.

"For the time being they are in a precarious but stable state. It's too early to be reassured though."