1999-05-16-01 Amniotic band syndrome © Jeanty www.thefetus.net/
Amniotic band syndrome
Updated 2006-01-18 by Juliana Leite, MD
Original text 1999-05-16 Philippe Jeanty, MD, PhD & Sandra R Silva, MD
Synonyms: ADAM complex (amniotic deformities, adhesion, mutilation), amniotic band sequence, amniotic disruption complex, annular grooves, congenital amputation, congenital constricting bands, stricter bands, transverse terminal defects of limb, aberrant tissue bands, amniochorionic mesoblastic fibrous strings, amniotic bands.
Definition: Amniotic band syndrome is a set of congenital malformations ranging from minor constriction rings and lymphedema of the digits to complex, bizarre multiple congenital anomalies that are attributed to amniotic bands that stick, entangle, and disrupt fetal parts.
Prevalence: The prevalence is 7.7/10.000 live births, but it can be as high as 178/10.000 for spontaneous abortions. The male-to-female ratio is 1:1.
Etiology: Not precisely known. Some theories have been suggested teratogenic, multifactorial, and genetic factors that cause a rupture of the amnion. Teratogenic effect of drugs such as methadone and lysergic acid diethylamide may play an important role in many cases.
Pathogenesis: Rupture of the amnion in early pregnancy leads to entrapment of fetal structures by “sticky” mesodermic bands that originate from the chorionic side of the amnion, followed by disruption. It has been suggested that the bands lead to a decreased blood flow in the constricted limb and subsequent natural amputation.
Diagnosis: The syndrome results in structural anomalies that vary from minor to lethal forms. The most common findings are constriction rings around the digits, arms, and legs; swelling of the extremities distal to the point of constriction; amputation of digits, arms, and legs; asymmetric face; facial clefts; cephalocele; anencephaly; acrania; multiple joint contractures; pterygium; clubfeet, clubhands, and pseudosyndactyly; microphthalmia, uveal coloboma, corneal metaplasia, and unilateral chorioretinal lacunae.
A detailed view of the fetus’ face, digits and body with 3-dimensional ultrasound exams, may contributed to the diagnosis.
Figure 1: Amputations of the fingers in a minor form of amniotic band1
Figure 2: The same fetus after delivery
Figure 3: A large facial cleft (white arrow) extends to the lens of the left eye1
Figure 4: Strands of amnion (arrows) are attached and move with the forehead1.
Figure 5 Multiple defects including facial clefts, cephalocele, amputations and abdominal wall disruptions1.
Differential diagnosis: A uterine synechia or septation can simulate an amniotic band. The amniotic folds can be differentiated since they are not “sticking” to the body.
Prognosis: The more severe forms are lethal. Mild manifestations sometimes are found just at birth and do not have impact on survival.
Recurrence risk: No recurrence expected, except in rare sporadic familial cases, which have been reported in association with epidermolysis bullosum and Ehler-Danlos syndrome.
Management: It depends on the extent of the anomalies. Termination of pregnancy can be offered for the severe forms. Recently, endoscopic release has been reported and may prove beneficial in releasing the constriction band in threatened limb amputation. Endoscopic fetal therapy with lysis of the constriction ring in utero is an option, but intervention is probably not always warranted. Spontaneous lysis of an amniotic band attached to a fetal elbow has been shown.
1. Paladini D, Foglia S, Sglavo G, Martinelli P. Congenital constriction band of the upper arm: the role of three-dimensional ultrasound in diagnosis, counseling and multidisciplinary consultation. Ultrasound Obstet Gynecol 2004;23(5):520-22
2. Chen CP, Chang TY, Lin YH, Wang W. Prenatal sonographic diagnosis of acrania associated with amniotic bands. J Clin Ultrasound 2004:32(5):256-60
3. Pedersen TK, Thomsen SG. Spontaneous resolution of amniotic bands. Ultrasound Obstet Gynecol 2001;18(6):673-74
4. Sentilhes L, Verspyck E, Eurin D, Ickowicz V, Patrier S, Lechevallier J, Marpeau L. Favourable outcome of a tight constriction band secondary to amniotic band syndrome. Prenat Diagn 2004;24(3):198-201
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