A baby boy in China has been born with an unusually well-formed third arm and doctors are considering surgical options for him.
According to Dr. Chen Bochang, head of the orthopedics department at Shanghai Children's Medical Center, tests have been unable to determine which was more developed as neither of the two-month old boy's two left arms is fully functional.
The case is it seems unusual as the third arm is so developed and in other children born with additional arms, legs, fingers, and toes they usually determine which to remove depending on how well it works.
The little boy also has only one kidney and has other problems that could lead to curvature of the spine.
The boy reportedly smiles and responds normally but cries when either of his left arms is touched.
At present doctors are trying to work out a plan for surgery, but the boy's small size makes it impossible to perform certain tests that would help them prepare.
Doctors will need to carefully analyze the anatomy and physiology through imagery such as X-rays and MRIs, which show bone structure and blood flow, as well as electro-diagnostic studies, which monitor nerve impulses from the brain to the muscle.
As a rule doctors usually wait until the child is six to 12 months old to perform any surgery, as they want to observe which extremity the child favors and uses most.
Media reports have revealed that other children have been born with additional arms and legs, but in all those cases it was clear which limb was more developed.
Shanghai Children's Medical Center is one of China's most experienced in dealing with unusual birth defects, including separating conjoined twins.