Controversial as to etiology, but simplest concept is entrapment of fetal parts by disrupted amnion

Asymmetric distribution of bizarre “slash” defects is hallmark of syndrome

Craniofacial deformities often severe; may look like anencephaly with singe orbit involvement

Abdominal wall defects are large, complex, often with complete evisceration

Extremities often involved

Body stalk anomaly: Fetus stuck to placenta, short cord

Developmental craniofacial and abdominal wall defects have defined anatomic distributions

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  Cephaloceles at suture lines (occipital most common)

  
  
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  Gastroschisis/omphalocele have characteristic appearance

Defects range from minor to lethal

Look for bands in any fetus with large abdominal wall or asymmetric craniofacial defect

Amniotic band may be tightly adherent and difficult to see

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  Look for restricted movement of involved area

  
  
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  Changing maternal position may “float” fetus away from uterine wall, revealing short band

  
  
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  Use high-resolution transducer for detailed assessment in near field

Edema of extremity distal to constricting band may progress to limb amputation

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  Use Doppler to check flow distal to constricting band

  
  
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  Abnormal, but present blood flow distal to band may identify cases suitable for fetal surgery