Fetal intra-abdominal bowel dilation in prediction of complex gastroschisis

Abstract

Objective To investigate intra-abdominal bowel dilation (IABD) in the prediction of complex gastroschisis. Methods This was a retrospective study of 174 singleton pregnancies with isolated fetal gastroschisis, resulting in live birth and with available ultrasound images from visits at both 20-22 and 30-32 weeks' gestation. IABD was measured as the greatest transverse diameter of the most dilated intra-abdominal bowel segment, by an operator blinded to postnatal outcome. The distribution of IABD measurements in those with complex and those with simple gastroschisis was determined and the best cut-off value to predict complex gastroschisis was selected using receiver-operating characteristics (ROC) curves. The area under the ROC curve (AUC), detection rate (DR), false-positive rate (FPR), positive predictive value (PPV) and negative predictive value (NPV) were determined. Results The study population included 39 (22.4%) cases of complex and 135 (77.6%) cases of simple gastroschisis. In the prediction of complex gastroschisis, the AUC at 20-22 weeks' gestation was 0.742 (95% CI, 0.628-0.856) and the respective value for 30-32 weeks was 0.820 (95% CI, 0.729-0.910). At the IABD cut-off of 7 mm at 20-22 weeks, DR, FPR, PPV and NPV for complex gastroschisis were 61.5%, 6.7%, 72.7% and 89.4%, respectively, and at IABD cut-off of 14 mm at 30-32 weeks, the respective values were 64.9%, 5.9%, 75.0% and 90.7%. Conclusion Measurement of IABD at 20-22 or at 30-32 weeks' gestation is useful in the prediction of complex gastroschisis.