Foetal ultrasound at 28 weeks demonstrates two adjacent fluid filled structures in the upper abdomen: a dilated stomach and a dilated proximal duodenum separated by the pylorus. Polyhydramnios is present. What is the most likely diagnosis?

• A Jejunal atresia
• B Oesophageal atresia with tracheo-oesophageal fistula
• C Congenital diaphragmatic hernia
• D Duodenal atresia ✓

Explanation

The double bubble sign, comprising a distended stomach and proximal duodenum divided by the pylorus, is pathognomonic of duodenal obstruction, most commonly duodenal atresia. About one third of affected foetuses have Down syndrome, so karyotyping is indicated. Jejunal atresia produces multiple dilated loops rather than a fixed double bubble, and oesophageal atresia typically shows an absent or small stomach with polyhydramnios.

Reference: Callen's Ultrasonography in Obstetrics and Gynecology, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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