Accuracy of antenatal ultrasound signs in predicting the risk for bowel atresia in patients with gastroschisis.

OBJECTIVE

Evaluate accuracy of prenatal ultrasound findings in predicting the risk of bowel atresia in patients with gastroschisis.

METHODS

A retrospective study was conducted on 18 fetuses with a prenatal diagnostic of gastroschisis treated at University hospital of Saint Etienne France between 2002 and 2012. Ultrasound abnormalities were used to classify them into three groups: no ultrasound abnormality (n=4), oligohydramnios (n=9), intra-abdominal bowel dilatation ≥20.5mm (n=5). Postnatal outcomes were compared between groups. The threshold value of 20.5mm for the prediction of atresia was determined through the receiver operator characteristics curve.

RESULTS

In the group with oligohydramnios, intra uterine growth restriction were significantly more frequent (p=0.015) and three newborns had serositis including two with secondary complications after the initial surgery. In the group with major intra-abdominal bowel dilatation, all had a narrow defect <10mm significantly more than other fetuses (p=0.002). Intra-abdominal bowel dilatation reaching 20.5mm started at a mean gestational age significantly lower than that of the other fetuses (23.3 versus 29.7 weeks p=0.02). On the five fetuses presented intra-abdominal bowel dilatation ≥20.5mm, four showed atresia and no other newborn has this complication (p=0.0016). The threshold value of 20.5mm has a sensitivity of 100% and a specificity of 92.9%. The area under the curve was equal to 96.4%.

CONCLUSION

Intra-abdominal bowel dilatation ≥20.5mm seems to be associated with the risk of postnatal atresia. MRI could help to clarify a complicated or uncertain ultrasound aspect.