Should we measure fetal omphalocele diameter for prediction of perinatal outcome?

Objective: To evaluate the fetal omphalocele diameter/abdominal circumference ratio (OD/AC) as a predictor of adverse perinatal outcome.

Methods: Analysis involving 47 singleton pregnancies with fetal omphalocele, normal karyotype and absence of other major abnormalities. The OD/AC ratio was determined antenatally by ultrasound and the best cutoff for the prediction of neonatal death was determined by receiver operating characteristic curve analysis. Additional secondary outcomes included need for oral intubation in the first 24 h of life, two-step surgery or use of synthetic mesh, reoperation, parenteral feeding and need for respiratory assistance >21 days, time to first oral feed, and time to hospital discharge.

Results: Fetal OD/AC did not change significantly with gestational age. Postnatal death occurred in 10 (21.3%) cases and the best cutoff for prediction was an OD/AC ratio ≥0.26. In pregnancies with the first ultrasound evaluation performed before 31 weeks' gestation and an OD/AC ≥0.26, the likelihood ratio for needing intubation in the first 24 h of life was 2.6 (95% CI: 1.2-5.7), needing two-step surgery or use of mesh was 4.9 (95% CI: 1.9-14.4), and postnatal death was 4 (95% CI: 1.9-7.5).

Conclusion: A fetal ultrasound OD/AC ratio ≥0.26 is associated with increased postnatal morbidity and mortality.