What is amniotic band syndrome?
Amniotic band syndrome is a well-know condition that can include a variety of different birth defects, usually affecting an arm or leg, fingers or toes. No two cases are alike – some are just a single malformation while others can include many disfiguring complications.
The upper body is involved more often than the legs or toes. (If you’re watching the current season of “The Bachelor” on TV, one of the women on the show is missing the lower part of an arm due to amniotic band syndrome.) Sometimes fingers or the lower portion of an arm are smaller than normal, sometimes they are missing all together, or occasionally some fingers may be webbed together. Sometimes a limb may have a deep groove around it showing where a tight band constricted growth.
In other cases, aside from defects of the arms or legs, a baby may also have facial defects (cleft lip or palate), a neural tube defect of the brain or spine, or have portions of internal organs protruding through a hole in the abdominal or chest wall.
The causes of amniotic band syndrome are yet unknown, but there are two main theories. One is that strands of tissue from the inside of the amniotic sac surrounding the developing baby separate from the lining and form bands that float free and entangle parts of the baby. If they wrap too tightly, they can restrict movement, blood flow and proper development, possibly even amputation. This may be due to random chance or trauma to the abdominal area and placenta during pregnancy.
Another theory holds that the cause stems from within the baby itself and involves insufficient blood flow to specific parts of the body. If an area of the body does not receive enough blood, tissues in that area die which can lead to physical defects. Some researchers believe that genetic factors may be involved in these cases. But whether this is caused from within the developing baby or from outside influences, occurrence is random and the chance of having another child with amniotic band syndrome is extremely low.
Treatment really depends on the severity of the defects. Surgery may be recommended to repair defects such as cleft lip or palate, clubfoot, or abdominal wall defects, etc. Sometimes physical or occupational therapies are needed to ensure the child has the best range of motion and use of the affected limb as possible.