amniotic band syndrome

(redirected from Streeter dysplasia)


pertaining to the amnion.
amniotic band syndrome a condition characterized by isolated or multiple constriction defects of the fingers, toes, limbs, and less frequently the skull, face, or viscera. It results from a tear of unknown etiology in the amnion, which allows amniotic fluid and fetal parts to escape from the amnion into the chorion. When the amnion and chorion are separated, strands from either the maternal amnion or the fetal chorion may entangle fetal parts. As the fetus grows the strands become more constrictive, causing defects.
amniotic fluid the albuminous fluid contained in the amniotic sac; called also liquor amnii and, informally, waters. The fetus floats in this fluid, which serves as a cushion against injury from sudden blows or movements and helps maintain a constant body temperature for the fetus. Normally the fluid is clear and slightly alkaline; discoloration or excessive cloudiness may indicate fetal distress or disease, as in erythroblastosis fetalis in which fluid is usually greenish yellow. The amount varies from 500 to 1500 ml.

An excessive amount of amniotic fluid (more than 2000 ml) is called hydramnios; the amount may be as much as several gallons. The cause of this condition is unknown but it frequently accompanies multiple pregnancy or some congenital defect of the fetus, especially hydrocephalus and meningocele.

An abnormally small amount of amniotic fluid is referred to as oligohydramnios; there may be less than 100 ml of fluid present. The cause is unknown. The condition may produce pressure deformities of the fetus, such as clubfoot or torticollis. Adhesions may result from direct contact of the fetus with the amnion.

Removal of a sample of amniotic fluid from the pregnant uterus is called amniocentesis.

amniotic band sequence

activity comprising early rupture of the amnion with formation of bands that adhere to or compress parts of the fetus, resulting in a wide variety of anomalies: craniofacial defects, amputation of a limb, and abdominal evisceration.

amniotic band syndrome

A triad of amnion-denuded placenta; foetal attachments to, or entanglement by, amniotic remnants; and foetal deformation, malformation or limb disruption.

amniotic band 'syndrome'

Obstetrics A triad of amnion-denuded placenta, fetal attachments to, or entanglement by, amniotic remnants, and fetal deformation, malformation, or limb disruption. See ADAM complex, Sequence.