Amniotic band syndrome (amniotic band syndrome) is a rare condition whose causes are still unknown. Its essence is damage to the developing tissues of the fetus by the disconnected strands of one of the amniotic membranes. What are the causes of amniotic tape syndrome? How is amniotic band syndrome diagnosed? What might its complications be? Is it possible to try the treatment before the baby is born?

Amniotic band syndrome( amniotic band syndrome ) may have different course and its consequences may take various forms - from single lesions, undergoing surgical reconstruction, to severe, complex and irreversible defects. The most common injuries concern the limbs of the fetus. Defects of the head, face and internal organs are slightly less common.

What is an amniotic?

The amniotic region is one of the four membranes that allow the embryo to develop. Each of the membranes has a slightly different structure and plays a separate role:

  • chorion, which is the fetal part of the placenta. It is located between the amnion and the uterine mucosa, thus enabling contact between the body of the fetus and mother
  • allantoin, accumulating metabolic products of the fetus
  • yolk sac containing yolk - supply of nutrients for the developing fetus
  • amniotic fluid, which forms a bladder around the fetus and is filled with amniotic fluid

The correct structure of the amniotic sac is necessary to maintain the continuity of the amniotic sac and to produce the amniotic fluid with the correct composition.

Specially built amniotic epithelium can, depending on the period of pregnancy, produce or absorb amniotic fluid.

Epithelial cells also maintain the correct concentration of amino acids and electrolytes in it.

The main role of the amniotic fluid is to allow the fetus to move, protect it from mechanical damage and prevent it from drying out.

Why can an amnion damage a fetus?

As can be seen from the previous point, the amnion is an essential structure that provides an optimal environment for the developing fetus. Why may the much-needed tissue cause injuries?

The essence of the amniotic band is to break the continuity of the amnion, while breaking it offfragments.

The outer layer of the fetal bladder - the chorion - remains intact. Broken strands of tissue either float freely in the amniotic fluid or are attached at one end to the rest of the amniotic membrane. These hyphae can become wrapped around any part of the fetus' body - fingers, limbs, neck, or torso.

If part of the strand is still connected to the amniotic bladder, the wrapped part of the body can be "stuck" to its wall. This causes a local development disorder and restricts the fetal movements.

In some cases of amniotic band syndrome, defects are described that are difficult to explain with the theory of detached amniotic fragments. These are, for example, serious damage to internal organs and various variants of a cleft palate.

Interestingly, in some cases of the development of the typical features of the amniotic band syndrome, no damage to the structure of the fetal bladder was visualized. For this reason, scientists propose an additional theory that the cause of the above-mentioned disorders may be fetal blood circulation disorders.

Risk factors for amniotic band syndrome are still being searched for. In most situations, the detachment of amniotic fragments is likely to be accidental. They are sometimes associated with mechanical trauma during pregnancy.

Despite intensive research, no specific genetic predispositions have been found that could result in the development of this syndrome.

The relationship with environmental factors (exposure to tobacco smoke, alcohol, drugs) and accompanying mother's diseases (e.g. diabetes, obesity) is also sought.

Understanding the complex causes of the amniotic band syndrome probably requires many more years of scientists' work.

Amniotic Band Syndrome: Symptoms

Amniotic band syndrome most often develops in the first trimester of pregnancy. Correctly developing parts of the fetus are tightly wrapped with amniotic bands, which inhibits their growth and prevents further development.

It is worth realizing that each fetus damaged as a result of this disease will present different disorders.

Amniotic bands most often wrap around the limbs, at different heights. This results in a sequence of symptoms that we can easily imagine: a tightly wrapped leg, handle or fingers of a child with distal swelling and severely impaired blood flow.

The most serious consequences of such damage include amputations or shortening of fingers and limbs and fusion of fingers or toes (syndactyly). Clubfoot is one of the most common limb defects accompanying the amniotic band syndrome.

Another variant of the amniotic band syndrome are various craniofacial defects. The most common pathology is cleft palate and / or lip cleft. Other disorders include nostril atresia, underdevelopment of the eyeballs, facial clefts, and changes in the size and shape of the skull bones.

Unfortunately, the amniotic band syndrome can also lead to fatal deformities - meningeal and spinal hernias, gastroschisis caused by cleft abdominal or thoracic integuments, or complete amputation of the head. Occasionally, fusion of the fetal head with the placenta is observed.

The detection of such severe, irreversible damage to the fetus is an indication for termination of pregnancy.

Amniotic Band Syndrome: Diagnostics

In many cases, amniotic band syndrome is not recognized until the baby is born. Typical changes in limbs, such as tightness in the place of wrapping, swelling, underdevelopment or fusion of the fingers, are a characteristic picture of this disease.

The diagnosis of the syndrome during pregnancy is quite difficult - the free strands of the amnias are very thin and not always visible on ultrasound.

  • Pregnant ultrasound

For this reason, it is very important to undergo regular checkups.

Sometimes the suspicion of the presence of such bands can be confirmed by tests that guarantee better image quality, e.g. with high-resolution ultrasound or during magnetic resonance imaging.

It is slightly easier to confirm the diagnosis if specific fetal abnormalities can be visualized. Abnormal appearance of the limbs, their swelling or uneven length are always a cause for concern.

In such cases, the diagnosis is made indirectly, by recognizing the effects of the syndrome, and not directly visualizing the disorders of the amniotic structure. The amniotic band syndrome should then be differentiated from other diseases that may lead to the above-mentioned. developmental defects.

Sometimes ultrasound shows amniotic strands, but no abnormalities in the development of the fetus. In such a situation, the mother and child must remain under strict control until delivery.

Interestingly, there are cases where, despite the existence of amniotic bands, no defects are formed and the baby is born he althy.

Amniotic Band Syndrome: Treatment

Can amniotic band syndrome be treated? The answer to this question largely depends on how severe the defects are in a given fetus.

The implementation of each type of therapy is tailored to the individual case.

Unfortunately, it happens that the amniotic band syndrome leads to lethal defects, i.e. making it impossible to survive. This condition is estimated to be the cause of 178 / 10,000 miscarriages.

  • Symptomatic treatment of the amniotic tape syndrome

In the case of limited disorders that do not cause such severe deformation of the fetus, various methods of treatment are used to achieve the best fitness and quality of life.

Anatomical defects, fusions or amputations of fingers or limbs are repaired surgically, using plastic and reconstructive surgery.

The procedure itself is never the end of treatment - appropriate rehabilitation is also often required, ensuring the best efficiency and functionality.

Surgical procedures are usually performed within weeks to months of birth. The exception is when blood flow disorders or vascular disorders have occurred - it requires immediate intervention.

Long-term pressure on nerve structures can lead to their atrophy and chronic pain syndromes - in this case, quick surgery and long-term rehabilitation are also necessary.

  • Prenatal surgery

All the methods mentioned above focus on treating the effects of the amniotic band syndrome.

There is also a possibility of causal therapy, i.e. prenatal surgery.

It involves performing an intrauterine surgery, even before the baby is born. The operator removes the amniotic strands, which pose a risk of limb amputation, for example.

Such a procedure requires early diagnosis and confirmation of the defect (usually by magnetic resonance imaging) and an in-depth analysis of the balance of potential benefits and risks for both the mother and the child.

About the authorKrzysztof BialaziteA medical student at Collegium Medicum in Krakow, slowly entering the world of constant challenges of the doctor's work. She is particularly interested in gynecology and obstetrics, paediatrics and lifestyle medicine. A lover of foreign languages, travel and mountain hiking.

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Category:

Pregnancy