10 Facts about Siamese Twins

Siamese twins (or conjoined twins) are a rare disorder characterized by siblings being joined together by one or more parts of their body. In the rarest of cases, the children are connected at the top of their heads. In this article, you will encounter facts and trivia regarding Siamese twins, including successful cases of separation.

Sometimes, Siamese twins are separated through surgery, where both of the siblings go onto to lead full, prosperous lives, but this is not always the case. Some parents must make the heartbreaking decision to let one twin die or move forward with a surgery that threatens the lives of both children.

1.    The phenomenon is rare for conjoined twins with an estimation of occurring from 1 in 50,000 births to 1 in 100,000 births. It seems to occur more frequently in Southwest Asia and Africa. About half of the children are brought into the world stillborn. A small fraction of twins are born alive, but have abnormalities that prevent them from leading a fulfilling life. Overall, the survival rate for conjoined twins is around 25%.

2.    Siamese twins are more frequently seen amongst females with a ratio of 3 to 1.

3.    The most well known of Siamese twins were Eng and Chang Bunker, who lived between 1811 and 1874. The Thai brothers were born in Siam , now known as Thailand. Their odd appearance secured them a place with the traveling P.T. Barnum circus, where they found employment for many years. They were advertised as the Siamese Twins. The brothers were connected by a band of flesh and cartilage. They shared fused livers inside of their torso. If they had been born during modern times, doctors could have easily separated the twins.

4.    The classification of conjoined twins falls into one of several different categories, which highlights the location at which the siblings bodies are connected. The most common types include thoraco-omphalopagus, thoracopagus, omphalopagus, parasitic, and craniopagus.

5.    Thirty-two percent of cases are thoraco-omphalopagus, where two bodies are fused at the upper chest to the lower chest. Typically, the twins share a heart and may also share the liver. Sometimes, they share part of the digestive system.

6.    Forty percent of conjoined twins are fused from the upper thorax to the lower belly. These kinds of cases are referred to as thoracopagus. The heart is always shared.

7.    Thirty-three percent of conjoined twins are called omphalopagus, where their bodies are fused at the lower chest. The difference in this type is that the heart is never involved. The twins often share a liver, diaphragm, digestive system and other organs.

8.    Seven percent of conjoined twins are called parasitic, which means that they are asymmetrically connected, where one of the twins is smaller and less formed. The small twin is dependent on the larger twin to survive.

9.    Two percent of conjoined twins are fused at the skull, but have separate bodies. This type of connection is called craniopagus. The twins could be conjoined at the back of the head, front of the head, or the side of the head , but never on the face or at the base of the skull.

10.    A famous pair of conjoined twins is Lori and George Schappell. The two have learned to respect one another’s boundaries and lead separate lives, including choosing their own professions and religion. George (who was born a woman) has performed as a country singer, while Lori works at a laundry and has an active dating life.