Objectives: To assess the accuracy of the prenatal ultrasound finding of subjectively small/absent stomach bubble in the prenatal diagnosis of tracheo-oesophageal fistula and oesophageal atresia (TOF/OA).
Methods: A retrospective study of prenatal ultrasound scans showing small/absent stomach bubble was carried out between 1st January 1994 and 31st December 2003.
Results: There were 62 cases with prenatally suspected (n = 40) and/or post-natally diagnosed (n = 22) TOF/OA. Among the 40 cases of prenatally suspected TOF/OA 15 were thought to be isolated and 25 non-isolated. Of the 15 suspected isolated cases, 7 were normal and 8 had TOF/OA (5 isolated + 3 TOF/OA with another anomaly) at delivery. Among the 25 cases of prenatally suspected non-isolated TOF/OA, there was confirmation in only two cases, in the remaining 23 cases other anomalies were confirmed but TOF/OA was not present.Twenty-two babies with TOF/OA were identified in whom there had been no prenatal ultrasound suspicion on ultrasound scanning. Six had isolated TOF/OA and 16 had non-isolated TOF/OA.
Conclusion: Of the 32 cases of confirmed TOF/OA,10 (31%) were suspected prenatally. If the TOF/OA was an isolated anomaly (11 cases), the prenatal detection rate was 45%. Interpretation of ultrasound findings suspicious of TOF/OA requires caution, particularly, when there are associated multiple anomalies on scan.