Esophagus atresia (EA) often associated with tracheoesophageal fistula (TEF)

Small or absent stomach bubble

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  Often difficult to define when stomach is “small”

  
  
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  Stomach size varies in same fetus over several hours

  
  
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  Because fetuses breathe amniotic fluid, small amount of fluid may get into stomach if there is TEF

  
  
  
  
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    Complete absence suggests no TEF

  
  

Pouch sign

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  Transient filling of proximal esophagus with swallowing

Fetal growth restriction seen in up to 40%

Polyhydramnios rarely develops before 20 weeks

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  Fetal swallowing not important part of amniotic fluid dynamics until that time

Risk for aneuploidy (trisomy 13 and 21)

> 50% have other anomalies

VACTERL (vertebral anomalies, anal atresia, cardiac malformation, TEF/EA, renal anomalies, limb malformations) association in 30%

US is poor in detecting EA before onset of polyhydramnios

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  Must have high degree of suspicion and perform follow-up scans in setting of small stomach

Perform focused exam looking specifically at neck and upper chest for esophageal pouch when stomach is small

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  Pouch will expand with fetal swallowing

  
  
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  Distinguish from normal hypopharynx anatomy

  
  
  
  
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    Trachea should be easily identified as separate nondistensible structure, relatively thicker wall, and connected to epiglottis

    
    
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    Esophagus located more posterior than trachea

  
  
  
  
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  Determine location of distal end of pouch

  
  
  
  
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    Termination in neck worse prognosis than termination in mediastinum