By Vinny Fuschetto CraniopagusThoraco-omphalopagus Parasitic twins

Craniopagus Fused skulls, but separate bodies. These twins can be conjoined at the back of the head, the front of the head, or the side of the head, but not on the face or the base of the skull. This condition occurs in conjoined twin in about 1 in every 2,500,000 births. 2% of most conjoined twins are combined in this way.

Thoraco-omphalopagus Two bodies fused from the upper chest to the lower chest. These twins usually share a heart, and may also share the liver or part of the digestive system. 28% of conjoined twins are combined in this way. This is the most common way people are conjoined.

Parasitic twins Twins that are asymmetrically conjoined, resulting in one twin that is small, less formed, and dependent on the larger twin for survival. 10% of all conjoined twins are combined in this way. One of the twins stops growing in the uterus and come out smaller then the other twin and relies on the other twin for everything.

Separation Separating conjoined twins can be more complex it matters where the twins are conjoined, the operation is extremely life threatening. In many cases, the surgery results in the death of one or both of the twins, particularly if they are joined at the head. Most doctors tell the patients to keep them conjoined because that is the best way of keeping them safe and alive./

Fun Facts The overall survival rate for conjoined twins is approximately 25%. The condition is more frequently found among females, with a ratio of 3:1. The occurrence of conjoined twins is estimated to range from 1 in 50,000 births to 1 in 100,000 births, with a somewhat higher incidence in Southwest Asia and Africa. Another word for conjoined twins is “ Siamese Twins”.