A 25-year-old British women in Austria has given birth to a set of identical triplets, something that only happens in one out of 200 million births.

Mae Christina Astley gave birth to three girls she called Amy, Kim and Zoe by Caesarean in western Austria Monday.

The babies, which were delivered four weeks' prematurely at 33rd week of pregnancy, weigh 3.3 pound each. The girls' father, 27-year-old Thomas Graziadei, says he is elated about their birth but admits it would be tough for him to differentiate one from another without their hospital wristbands on.

Normally, the triplet foetuses are extremely rare because it means the original fertilized egg split and then one of the resulting cells split again. Most of them die early on in a pregnancy.

According to AAP, the Austrian press, to make sure that the babies are healthy, hospital authorities have kept then in the intensive care unit for at least two to three weeks. The triplets were conceived naturally, without any fertility treatments.