Conjoined Twins
Abby & Brittany Hensel



Conjoined Twins
Abby & Brittany Hensel


Abby & Brittany were born on March 7th, 1990. They have two spines and separate half-sacrums, which converge distally within a slightly broad pelvis.

Each controls and senses her corresponding arm and leg; a third, rudimentary central arm was amputated in infancy.


Abigail "Abby" Loraine Hensel and Brittany "Britty" Lee Hensel (born March 7th, 1990, Carver County, Minnesota, United States), are highly symmetric dicephalic parapagus conjoined twins.

They have two spines and separate half-sacrums, which converge distally within a slightly broad pelvis. Each controls and senses her corresponding arm and leg; a third, rudimentary central arm was amputated in infancy.

They were raised in New Germany, Minnesota and attended Lutheran High School affiliated with the Missouri Synod in Mayer, Minnesota. At age 12, they underwent surgery at Gillette Children's Specialty Healthcare to correct scoliosis and to expand their chest cavity to prevent future difficulties with breathing.

Each of the twins manages one side of their conjoined body and are quite effective in cooperatively using their limbs when both hands or both legs are required.

By coordinating their efforts, they are able to walk, run and ride a bicycle normally - all tasks that they learned at a normal speed.

Each writes with her hand. Together, they can type on a computer keyboard at a normal speed.

They had 2 hearts which, however, are in a shared circulatory system (nutrition, respiration, medicine taken by either affects both).

Most of their shared organs are located at or below the level of their shared navel.


Conjoined twins (also known as Siamese twins) are identical twins whose bodies are joined in utero. A rare phenomenon, the occurrence 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.

Approximately half are stillborn, and a smaller fraction of pairs born alive have abnormalities incompatible with life. The overall survival rate for conjoined twins is approximately 25%. The condition is more frequently found among females, with a ratio of 3:1.

Two contradicting theories exist to explain the origins of conjoined twins. The older and most generally accepted theory is fission, in which the fertilized egg splits partially. The second theory is fusion, in which a fertilized egg completely separates, but stem cells (which search for similar cells) find like-stem cells on the other twin and fuse the twins together.

Conjoined twins share a single common chorion, placenta, and amniotic sac, although these characteristics are not exclusive to conjoined twins as there are some monozygotic but non-conjoined twins that also share these structures in utero.

The most famous pair of conjoined twins was Chang and Eng Bunker (Thai: อิน-จัน, In-Chan) (1811–1874), Thai brothers born in Siam, now Thailand. They traveled with P.T. Barnum's circus for many years and were billed as the Siamese Twins.

Chang and Eng were joined by a band of flesh, cartilage, and their fused livers at the torso. In modern times, they could have been easily separated. Due to the brothers' fame and the rarity of the condition, the term came to be used as a synonym for conjoined twins.