An Australian woman has given birth to identical quadruplet girls after a pregnancy doctors described as incredibly rare.

Jenitar Sau Na’amoana, who is 34 years old and already had four children, delivered the babies last week at Royal Brisbane and Women’s Hospital in Queensland state.

"We are very excited to be able to care for this amazing little family, a big family now,” Dr. Alexa Bendall, a maternal fetal medicine specialist who cared for Na’amoana, said in an interview released by the hospital.

The babies were conceived naturally and came from one fertilized egg that split into four, "which was incredible," Bendall said.

"We think the figures are probably around 1 in 15 million for a case like this to be spontaneously conceived,” she said. "We don’t think it’s ever happened in Australia.”