Related Disorders List

Information on the following diseases can be found in the Related Disorders section of this report:

• Pierre Robin Syndrome
• Clubfoot
• Bilateral Renal Agenesis
• Potter Syndrome
• Polycystic Kidney Disease

Symptoms

If amniotic band formation takes place early during pregnancy, resulting abnormalities of the developing fetus may be very serious and the condition may result in miscarriage. If rupture of the amniotic sac occurs later during pregnancy, Amniotic Bands may or may not develop.

When amniotic band formation occurs, the fibrous bands may encircle, entangle, and/or gradually constrict certain fetal areas. As a result, there may be decreased fetal movements, abnormal accumulations of fluid within bodily tissues, localized tissue loss, and/or other abnormalities. Although associated structural deformities vary greatly from case to case, such malformations may include deep rings or grooves encircling the arms or legs (limbs); underdevelopment (hypoplasia), absence, or "amputation" of particular limbs; and/or malformations of fingers and/or toes (digits). Some affected newborns may have abnormal sideways curvature of the spine (scoliosis); foot deformities (clubfeet); and/or incomplete development of the lungs, resulting in difficulties breathing (respiratory insufficiency). In addition, in cases in which amniotic band formation occurs early during fetal development, additional malformations may be present, such as incomplete closure of the roof of the mouth (cleft palate), a groove in the upper lip (cleft lip), other facial abnormalities (facial clefts), malformations of the skull, and/or deformities of the chest and abdominal regions.

Causes

Amniotic band formation usually appears to occur randomly for unknown reasons (sporadically). Some researchers suggest that, in rare cases, there may be certain predisposing factors that may increase the risk of amniotic band development. These may include blunt trauma to the abdominal area during pregnancy, performance of a diagnostic technique during which amniotic fluid is removed from the amniotic sac and analyzed to detect particular fetal abnormalities (amniocentesis), or certain genetic connective tissue diseases (e.g., Ehlers-Danlos syndrome, osteogenesis imperfecta).

Affected Populations

Amniotic bands appears to occur more frequently among male fetuses than among females. The condition is thought to affect approximately one in 10,000 newborns.

Related Disorders

Symptoms of the following disorders can be similar to those of Amniotic Bands. Comparisons may be useful for a differential diagnosis:

Pierre Robin Syndrome in an infant is characterized by an unusually small jaw (micrognathia), downward displaced tongue (glossoptosis), and cleft soft palate. The tongue may obstruct normal breathing. Problems in breathing may lead to lung malfunction and enlargement of part of the heart (cor pulmonale), high blood pressure in the lung's arteries (pulmonary hypertension), and possibly lead to congestive heart failure. This disorder may result from mechanical constraint of the fetus in the womb due to lack of amniotic fluid. It may also be inherited as an autosomal recessive trait, or result from certain drugs taken by the mother during pregnancy. (For more information on this disorder, choose "Pierre Robin" as your search term in the Rare Disease Database.)

Clubfoot is a word used for several kinds of ankle and foot deformities usually present at birth. The defect can be mild or severe, and it can affect one foot or both. Clubfoot probably is caused by a combination of hereditary and other factors that may affect prenatal growth, such as mechanical constraint (lack of amniotic fluid), infection, drugs taken during pregnancy, diseases and other factors in the maternal environment. (For more information on this disorder, choose "Clubfoot" as your search term in the Rare Disease Database.)

Bilateral Renal Agenesis is the absence of both kidneys at birth. It is characterized by the failure of the fetus to develop kidneys. This absence of fetal kidneys is the primary cause of the deficiency of amniotic fluid (Oligohydramnios) in the pregnant mother. (For more information on this disorder, choose "Bilateral Renal Agenesis" as your search term in the Rare Disease Database.)

Potter's Syndrome (Oligohydramnios tetrad), results from the lack of amniotic fluid caused by a defect of urinary output from the fetus, or by chronic leakage of fluid from the amniotic sac. Potter's Syndrome is characterized by an unusual face, underdevelopment of the lungs, limb deformities, and inadequate or missing kidneys.

Polycystic Kidney Disease is characterized by many cysts in both kidneys. This causes enlargement of the total kidney size, while reducing the functional kidney tissue by compression. The infantile form of Polycystic Kidney Disease is present at birth with characteristic low output of urine. (For more information on this disorder, choose "Polycystic Kidney" as your search term in the Rare Disease Database.)

Standard Therapies

Diagnosis
Amniotic bands is typically diagnosed at or soon after birth based upon characteristic physical findings. According to some researchers, minimal diagnostic criteria consist of detection of certain abnormalities of the arms, legs, fingers, and/or toes, i.e., ring-like constriction or amputation defects.

In some cases, the condition may be suspected before birth (prenatally), based upon the results of certain specialized imaging techniques, such as fetal ultrasonography. During fetal ultrasonography, reflected high-frequency sound waves are used to create an image of the developing fetus. In addition, in some cases, laboratory testing may detect elevated levels of alpha-fetoprotein (AFP) in the fluid surrounding the fetus (amniotic fluid). Alpha-fetoprotein, a protein produced by the fetal liver, is excreted in urine into the amniotic fluid. Raised AFP levels may be associated with a number of abnormalities in a developing fetus (e.g., neural tube defects, congenital nephrosis, esophageal atresia, etc.) or may occasionally be present when the fetus is developing normally.

Treatment
The treatment of infants and children with amniotic bands is symptomatic and supportive. For example, in infants with incomplete development of the lungs and associated respiratory insufficiency, treatment may include oxygen support measures and other supportive therapies as required. Plastic surgery or other surgical techniques may be recommended to help correct or repair associated malformations, such as ring-like constrictions of the limbs.

Investigational Therapies

The artificial instillation of amniotic fluid is a form of treatment under investigation by scientists for women with severe lack of amniotic fluid (oligohydramnios). This procedure is being tried only on an experimental basis when conservative measures have proven ineffective. More studies are needed to indicate safety and effectiveness of this procedure.

References

McKusick VA, ed. Online Mendelian Inheritance in Man (OMIM). Baltimore. MD: The Johns Hopkins University; Entry No:217100; Last Update:8/16/94.

TEXTBOOKS
Jones KL, ed. Smith's Recognizable Patterns of Human Malformation. 5th ed. Philadelphia, PA: W. B. Saunders Co: 1997:636-647.

Buyce ML, ed. Birth Defects Encyclopedia. Dover, MA: Blackwell Scientific Publications; For: The Center for Birth Defects Information Services Inc; 1990:97-98.

Gorlin RJ, et al., eds. Syndromes of the Head and Neck, 3rd ed. New York, NY: Oxford University Press; 1990:11-14.

REVIEW ARTICLES
Walter JH Jr, et al. Amniotic band syndrome. J Foot Ankle Surg. 1998;37:325-33.

Bahadoran P, et al. Congenital constriction band of the trunk. Pediatr Dermatol. 1997;14:470-472.

Bagatin M, et al. Craniofacial manifestations of the amniotic band syndrome. Clin Pediatr Med Surg. 1997;116525-116528.

Moore MH. Rare craniofacial clefts. J Craniofac Surg. 1996;7:408-411.

JOURNAL ARTICLES
Chihara H, et al. Prenatal diagnosis of succenturiate lobe by ultrasonography and color Doppler imaging. Arch Gynecol Obstet. 2000;263:137-138.

Strauss A, et al., Intra-uterine fetal demise caused amniotic band syndrome after a standard amniocentesis. Fetal Diagn Ther. 2000;15:4-7.

Nagore E, et al., Radius hypoplasia, radial palsy, and aplasia cutis due to amniotic band syndrome. Pediatr Dermatol. 1999;16:217-219.

van der Meulen JC. The amniotic band syndrome. Plast Reconstr Surg. 1999;103:1087-90.