Amniotic constriction bands

Alternative names:

pseudo-ainhum; Streeter's dysplasia

Definition:

Defects caused in the limbs (arms or legs) or digits (fingers or toes) by entrapment in fibrous amniotic bands while in utero.

Causes, incidence, and risk factors:

Damage to the amnion (part of the placenta) may produce fibrous bands that can entrap the limbs of the fetus. These bands compress the area of the limb over which they run reducing blood supply and causing the limb to develop abnormally. On rare occasion, a complete "natural" amputation of a digit, digits, or limb can occur before birth. Cosmetic appearance of the limbs can be corrected surgically. The relative incidence is low, and exact figures are not available.