Measurement of Gastric Circumference in Foetuses with Oesophageal Atresia

Background: The specific recognition of oesophageal atresia (OA) with or without a tracheal fistula in a foetus is a diagnostic challenge for prenatal medicine. The aim of the present work is to analyse the value of the measurement of gastric size in the diagnosis of this significant malformation. Materials and Methods: Altogether, the examinations of 433 pregnancies between the 18.4 and 39.1 weeks of gestation were retrospectively analysed. 59 of these foetuses exhibited an OA. By means of a linear regression analysis with normal foetuses, significant parameters influencing gastric size were examined. Subsequently the gastric sizes were transformed into z values and a comparison was made between OA with and without fistulae with the help of t tests. Results: In the normal foetuses there was a significant association between the gastric circumference and the abdominal circumference (circumference = 6.809 + 0.179 × abdominal circumference, r = 0.686, p < 0.0001). In the normal group the average was 43.0 (standard deviation [SD] 13.7) mm and those in foetuses with and without fistuale were 33.8 (SD 22.7) and 0.9 (SD 3.7) mm. In 34 (57.6 %) foetuses with an OA, the gastric circumference was below the 5th percentile. In detail, there were 13 (34.2 %) foetuses with a fistula and 21 (100 %) without a fistula. The average z values in the normal group and in the groups of OA with fistula and without fistula amounted to 0.0 (SD 1.0), -1.3 (SD 2.2) and -4.5 (SD 1.0). Conclusion: Measurements of the gastric circumference below the 5th percentile should lead to further diagnostic measures, especially when associated with polyhydramnios. Although OA without a fistula is always conspicuous, only about one in three OAs with fistula are associated with a significantly smaller stomach.