HOW GOOD IS ULTRASOUND IN THE DETECTION AND EVALUATION OF ANTERIOR ABDOMINAL-WALL DEFECTS

The ability of routine obstetric ultrasound to detect and accurately describe fetuses with anterior abdominal wall defects has been examined in an unselected population using data from a regional abnormality survey. Examination between 16 and 22 weeks gestation detected 60% of defects with a false positive rate of 5.3%. Fetuses with gastroschisis were incorrectly assigned as exomphalos in 14.7% of cases recognized before 22 weeks gestation. The diagnosis, including description of associated detectable anomalies, was completely accurate in 71.6% of cases. Some of the problems of diagnostic accuracy need to be considered when counselling couples with a fetal anomaly. Cross-referral between obstetric ultrasound units should be encouraged to improve diagnostic accuracy. These results form the basis for audit of obstetric ultrasound in the diagnosis of fetal abnormality within a geographically defined population.