Tregear woman Renee Young has given birth to twin girls born with a very rare medical condition called diprosopus.
The girls, named Hope and Faith, share a heart, a body, limbs and a skull, but they each have their own brain and a set of identical facial features.
Ms Young and her partner Simon Howie, parents to seven other children, said the girls were doing well after being born on Thursday.
“They are breathing perfectly on their own and feeding,” Mr Howie told Woman's Day.
“They even had their first bath last night. We have no idea how long they will be in hospital. We just want to bring them home, happy and healthy to make our family a little bit bigger and a bit more chaotic.”
The couple discovered during an ultrasound at 19 weeks into the pregancy that the girls would be born with diprosopus, also known as cranialfacial duplication.
Doctors told the couple that they should consider terminating the pregnancy.
Developmental issues meant the babies might have difficulty breathing once they were born.
But they decided to go ahead with the pregnancy and at 32 weeks, Ms Young gave birth by emergency caesarean at Blacktown Hospital.
The twins weighed just over two kilograms.
“Even though there is only one body, we call them our twins,” Mr Howie told Woman's Day.
“To us, they are our girls and we love them.”
There have been only 35 similar cases recorded worldwide and none of those babies survived.
Foetal specialist Dr Greg Kesby said in Feburary that a good outcome for the pregnancy would be difficult.
"In fact, some would say impossible to get to a good outcome. But people’s definition of good varies and, to them, they want to enjoy the fact that they have a daughter and they want their family of seven others to enjoy the pregnancy.”