Amniotic bands are a rare occurrence in utero due to a rupture of the inner sac, or amnion, that surrounds the baby.
The remaining fibrinous strings of tissue, or bands, can damage the growing fetus if they come into contact with the baby. The strings may wrap around the baby’s arms, legs, fingers, or toes, putting pressure on the body parts. As the baby grows, these areas can become indented, leaving a crease in the outer layers of skin. If severe, these bands can even cause amputation of the area it affects.
Fortunately, this condition only affects 1 in every 1,200 to 15,000 live births. Recently, in utero surgery has been performed to loosen the bands in an attempt to save a constricted extremity. However, reconstructive surgery on the affected body part is often needed after birth.
Reviewed by Dr. Sara Connolly, August 2019