Potential for a normal fetal stomach to simulate the sonographic "double bubble" sign

Area of Science:

• Fetal imaging
• Diagnostic ultrasound
• Gastrointestinal development

Background:

• Prenatal diagnosis of fetal gastrointestinal anomalies is crucial.
• Duodenal atresia is a significant congenital anomaly requiring prompt surgical intervention.
• Ultrasonography is the primary modality for fetal anomaly screening.

Observation:

• The normal fetal stomach, particularly with a prominent incisura angularis, can present an ultrasonographic appearance similar to duodenal atresia.
• This potential for misinterpretation highlights the importance of detailed sonographic assessment.

Findings:

• The key differentiating features include the absence of polyhydramnios, which is typically associated with duodenal atresia.
• Real-time ultrasound assessment in planes traversing the long axis of the fetal stomach is essential for accurate evaluation.
• Identifying the normal anatomy of the stomach and pylorus can exclude duodenal obstruction.

Implications:

• Accurate differentiation prevents unnecessary interventions and parental anxiety associated with false-positive diagnoses of duodenal atresia.
• Emphasizes the need for standardized protocols in fetal stomach sonography.
• Improves the diagnostic accuracy of prenatal ultrasound for gastrointestinal abnormalities.