What is the definition of Amniotic Band Syndrome?
Amniotic band syndrome refers to a condition in which bands develop from the inner lining of the amnion. The amnion is the sac that surrounds the baby in the womb. As the baby develops in the womb, the bands may attach to and affect the development of different areas of the body. This may result in constriction of the affected area or even amputation. The signs and symptoms vary greatly depending on the area(s) of the body involved and may include: shortened or absent digits (fingers and/or toes) or limbs (arms and/or legs), an opening in the abdomen through which various abdominal organs can protrude (abdominal wall defects), protrusion of a portion of the brain and its surrounding membranes through a skull defect (encephalocele), and cleft lip and/or palate. In most instances, the cause of amniotic bands remains unknown. Researchers have suggested two main theories to explain the development: the extrinsic theory and the intrinsic theory. The extrinsic theory states that amniotic band syndrome occurs due to factors found outside of the developing baby (externally); the intrinsic theory states that amniotic band syndrome occurs due to factors found within the baby (internally). Treatment differs depending on the severity of the condition and the areas of the body affected and may include surgery, physical therapy, and occupational therapy.
What are the alternative names for Amniotic Band Syndrome?
- Amniotic bands sequence
- Familial amniotic bands
- Streeter anomaly
- Congenital constricting bands
What are the causes for Amniotic Band Syndrome?
Amniotic bands are caused by damage to a part of the placenta called the amnion. Damage to the amnion may produce fiber-like bands that can trap parts of the developing baby.
What are the symptoms for Amniotic Band Syndrome?
The symptoms of amniotic band syndrome depend on the severity and location of the constrictions. The mildest constrictions affect only the superficial skin and may not require treatment. Deeper constrictions may block lymphatic vessels, impair blood flow, and require immediate surgical care. When the bands affect the limbs, the lower part of the limbs are most often involved, especially the middle, long, and index fingers of the hand. When the feet are involved, the bands most commonly affect the big toe.
Pressure from the bands may result in additional abnormalities, such as underdevelopment of a limb, bone abnormalities, amputations, leg-length discrepancy, and club feet. Constriction bands across the head and face may lead to facial clefts. Severe clefts affecting vital organs are often life-threatening.
What are the current treatments for Amniotic Band Syndrome?
Mild cases may not require treatment, however all bands need monitoring as growth occurs to watch for progressive constriction and swelling. Other constrictions may require surgical management; surgical options will vary depending on the abnormality. People with amniotic band syndrome who have amputations may benefit from the use of prosthetics.
What is the outlook (prognosis) for Amniotic Band Syndrome?
Because the prognosis of people with amniotic band syndrome can vary from patient to patient, the best person to provide your family with information regarding your child's prognosis, is the health care providers involved in their care. In general, the outlook for infants with a single band involving the superficial skin of the wrist and/or hand is good. While the family and child will need to adjust to the cosmetic difference, the functional use of the hand is normal. Deeper bands can be associated with complications (i.e., blockage of lymph and blood vessels) that can worsen over time and may require surgery. Some people with amniotic band syndrome are born with acrosyndactyly, a fusion of the fingers that may limit the hand function and cause stiffness of the joints. In many cases a good ability to hold and grasp may be obtained with reconstructive procedures.
How is Amniotic Band Syndrome diagnosed?
The earliest reported detection of an amniotic band is at 12 weeks gestation, by vaginal ultrasound. On ultrasound the bands appear as thin, mobile lines, which may be seen attached to or around the baby. However these bands may be difficult to detect by ultrasound, and are more often diagnosed by the results of the fusion, such as missing or deformed limbs.