1.   The twins were joined together at birth and had to be separated in a very delicate operation.

2.   It is unknown whether the parents knew that their twins were joined before delivery.

3.   When twins are joined at the chest, their chances for survival drop dramatically.

4.   But progress has been slow because the twins were joined for so long, their doctor Keith Goh earlier told The Associated Press.

5.   Most Siamese twins are joined at the abdomen or hip, not at the head, Hoffman said.

6.   Most Siamese twins are joined at the chest, he said.

7.   The separation process would start with the pelvic bones and then go to the spines, where the twins were joined.

8.   The separation process was expected to start with the pelvic bones and then go to the spines, where the twins were joined.

9.   The girls parents David and Emma Mowatt decided not to abort the pregnancy when doctors told them that their twins would be joined.