Siamese Twin Facts

Whether you see them on the street or on CNN, Siamese twins are hard to ignore. Conjoined, or Siamese, twins are attached to their identical twin at the head, chest or back. It's hard to believe that this amazing phenomenon is the result of some pretty simple science.

How Siamese Twins Develop

Siamese twins develop the same way that identical twins do - with one major difference. While identical twins (twins who look exactly the same) are formed inside a woman's uterus (womb) when a fertilized egg splits in two, Siamese twins form when the egg starts to split but stops part way through. Each side of the partially divided egg turns into a fetus (unborn baby). Siamese twins occur in animals - such as cats and snakes - not just people.

How Common Are Siamese Twins?

Siamese Twins are extremely rare. They occur about once per 100,000 pregnancies. Often times, only one half of the attached eggs will develop into a baby, while the other side doesn't, so babies are sometimes born with the undeveloped twin attached to them.

Separating Siamese Twins

No matter how they look on the outside, Siamese twins are two different people with different ideas and interests. Normally doctors will try to separate the twins if they can. The success rate of these surgeries vary depending on where the twins are attached and what organs they share, but it's usually pretty risky. In 2003, 29 year-old Siamese twins from Iran had surgery to be separated but both died. However, about 75 percent of separations are successful.

Siamese Twins - Did U Know?

• Siamese twins get their name from the famous conjoined twins Chang and Eng who traveled with the Barnum and Bailey circus in the 1800s. They were from Siam, now known as Thailand.
• The first successful separation of Siamese twins occurred in 1956.
• Actor Andy Garcia (The Godfather III) was born with his undeveloped twin brother attached to him.
• Most Siamese twins are female.
• Most Siamese twins are attached at the chest.

I think that it was sad that the twins died. I feel really bad. The thing that really surprised me was that they took the risk and both of them died.

Kidz Submit by:

Nickname: sk8ergirl4avril
Age: 10

Related Stories:

• Celebrity Twins
• Separated At Birth: Skeet Ulrich and Johnny Depp
• The Sedin Twins
• Quiz! Name That Olsen Twin
• More Cool Science Facts!