RESUMEN
OBJECTIVE: To investigate the relation between prenatal ultrasound measurements of viscero-abdominal disproportion and the expected type of postnatal surgical closure of an omphalocele. STUDY DESIGN: Retrospectively, 24 fetuses diagnosed with an isolated omphalocele in the 2nd trimester of pregnancy were selected (period 2003-2013). An image of the axial plane of the abdomen at the level of the defect was retrieved. The ratio of omphalocele circumference to abdominal circumference (OC/AC), and the ratio of defect diameter to abdominal diameter (DD/DA) were calculated. Prognostic outcome was primary closure. Sensitivity and specificity and the corresponding area under the ROC curve of these ratios were calculated as measurements of prognostic accuracy. RESULTS: Primary closure was achieved in 15/24 cases. For the OC/AC-ratio a cut-off value of 0.82 successfully predicted outcome in 23/24 cases with an area under the ROC curve of 0.99. A cut-off value of 0.61 for the DD/DA-ratio successfully predicted type of closure in 20/24 cases with an area under the ROC curve of 0.88. In all cases without eviscerated liver tissue, the defect was primarily closed. CONCLUSION: In prenatal isolated omphalocele cases, the OC/AC-ratio is better at predicting postnatal surgical closure than the DD/DA-ratio and can be used as a prognostic tool for expected type of closure in the 2nd trimester of pregnancy.