Amniotic constriction bands

Definition

Amniotic constriction bands are strands of fluid-filled sacs that surround a baby in the womb. They may cause a congenital (present from birth) deformity of the arms, legs, fingers, or toes.

Alternative Names

Causes, incidence, and risk factors

Amniotic constriction bands are caused by a type of damage to a part of the placenta called the amnion. The placenta carries blood to a baby still growing in the womb. Damage to the placenta can prevent normal growth development.

Damage to the amnion may produce fiber-like bands that can trap the arms, legs, fingers, or toes of the fetus. These bands reduce blood supply to the areas and cause them to develop abnormally.

Amniotic constriction bands are relatively rare.

Symptoms

• Permanent band or indentation around an arm, leg, finger, or toe
• Baby may be born with all or part of an arm or leg missing (congenital amputation)
• Abnormal gap in the face (if it goes across the face, it is called a cleft)
• Defect of the abdomen or chest wall (if band is located in those areas)

Signs and tests

Physical examination is sufficient to make this diagnosis.

Treatment

The severity of the deformity can vary widely from only one toe or finger being affected to an entire arm or leg missing or being severely underdeveloped. Therefore, the treatment varies widely. Often, the deformity is not severe and there is no treatment needed. In more serious cases, major surgery may be needed to reconstruct all or part of an arm or leg.

Expectations (prognosis)

Again, the prognosis depends on the severity of the disease. Most cases are mild and the prognosis for normal function is excellent. More involved cases have more guarded prognoses.

Complications

Complications can include complete or partial loss of function of an arm or a leg. Congenital bands affecting the hand are the most problematic.

Calling your health care provider

This disease is usually diagnosed at birth.