Paper Ethics

I. Introduction Conjoined twins are identical twins whose body part/s is fused together. It is because they do not fully separate from each other due to incomplete division of the fertilized ovum. They will be connected at certain points of the body and may tissues, organs or limbs. It is a rare case and only few of them survive. For some reason, female conjoined twins have more shot for survival than their male counterparts. Approximately 70% of conjoined twins are female. Conjoined twins are genetically identical. Thus, they always have the same sex. They develop from the same fertilized egg, and they share the same amniotic cavity and placenta. Twinning occurs by the either releasing of two eggs by the woman instead of the usual one or she produces only one egg that divides after fertilization. If she releases two eggs, which are fertilized by separate sperm, she has fraternal twins. When a single, fertilized egg divides and separates, she has identical or paternal twins. In the case of conjoined twins, a woman only produces a single egg, which does not fully separate after fertilization. The developing embryo starts to split into identical twins during the first few weeks after conception, but stops before the process is complete. The partially separated egg develops into a conjoined fetus. There are different types of conjoined twins and they are classified according to the place on the body where the twins are connected. The types of conjoined twins are as follows:  Upper trunk and head (front/back) Cephalopagus - A rare form of conjoined twins that are joined from the top of the head down to the umbilicus, with a separate lower abdomen and pelvis. Two fused faces are on opposite sides of the head.  Head Craniopagus - Conjoined twins that are connected only at the cranium (head). They share bones of the skull and occasionally brain surface, but will have separate trunks, with four arms and four legs. About 2% of conjoined twins are craniopagus.

 Brain, head and chest Epholothorapagus - A combination of cephalopagus and thoracopagus conjoined twins. The twins are joined at the head and chest, sharing a brain, fused hearts and gastrointestinal tracts.  Trunk (front/back) Omphalapagus - One of the most common type of conjoined twins, these individuals share an anterior connection of the trunk, usually at the abdomen, but the connection can range from the thorax down to the umbilicus. Omphalopagus twins may share a liver, gastrointestinal or genitourinary functions, bur rarely share a heart. There are four arms, four legs and two pelvises.  Rear end Pygopagus - Conjoined twins that are connected at the posterior (rump). Pygopagus twins, about 19% of conjoined sets, have separate hearts but may share a spinal cord. There is one anus, two rectums, four arms and four legs.  Chest (side to side) Thoracopagus - The most common type of conjoined twins, these individuals share an anterior (face-to-face) connection of the upper half of the trunk, through the chest wall from the thorax down to the umbilicus. Thoracopagus twins almost always share a heart. There are four arms, four legs and two pelvises.  Lower body (side to side) Parapagus - Conjoined twins that share a lateral connection of the lower half of the body. The connection between upper body varies. The heart may or may not be shared.  Lower body (front/back) Ischipagus - A rare type of conjoined twins that share an anterior connection of the lower half of the body. The heart is not involved.

One of the earliest documented cases of conjoined twins were Mary and Eliza Chulkhurst. They were born in Biddenden, County of Kent, England in the year 1100, and were joined at the hip. Another set of famous conjoined twins was Eng and Chang Bunker, who were born in Thailand (then called Siam) in 1811. The term Siamese twins was coined as a reference to Eng and Chang, who achieved international fame shortly after leaving Siam as teenagers. They were joined at the lower chest and shared their liver. Throughout history, conjoined twins have appeared in myths and legends. An example would be the Greek and Roman god Janus who had two faces, one young, one old.

Continuation about the past beliefs about conjoined twins... then how technology now has affecting conjoined twins. To separate or not to separate?