Evaluation of the Accuracy of Prenatal Ultrasound Assessment of Facial Clefts

Abstract

Objective: To evaluate the accuracy of two-dimensional and three-dimensional ultrasound in the diagnosis of facial clefts, and particularly in predicting the presence or absence of associated alveolar cleft / cleft palate in the presence of cleft lip.
Methods: All cases of facial clefts diagnosed before 24 weeks over a 5-year period from 2009 to 2013 in a single obstetric unit were reviewed. The findings from conventional two-dimensional ultrasound scanning and three-dimensional ultrasound imaging, using the reverse face view, oblique face view, or other modified techniques were compared with the findings at postnatal examination of the babies or at pathological examination of the fetuses after termination of pregnancy. The degree of accuracy of prenatal diagnosis of cleft lip alone, or cleft lip with alveolar cleft / cleft palate was determined.
Results: A total of 42 cases were analysed. There were 35 unilateral, six bilateral, and one median cleft lips.
Three cases involved a fetus of a monochorionic twin pair, and one case involved a fetus of a dichorionic twin pair. Associated structural abnormalities were detected by antenatal ultrasound in five cases, and significant karyotype abnormalities were detected in four cases. Termination of pregnancy was performed in 13 cases. There were 12 cases with cleft lip only, six cases with cleft lip with associated alveolar cleft, and 24 cases with cleft lip and palate. There were five cases where antenatal ultrasound overdiagnosed the severity of the cleft, while in three cases the extent of the cleft was underdiagnosed, giving an overall accuracy of 81%. The most common discrepancy was in the overdiagnosis or underdiagnosis of alveolar clefts, whereas there were no errors concerning the side of the cleft. When only the antenatal diagnostic accuracy of presence or absence of palate clefts was calculated, the overall accuracy was 95% (40/42; Phi value, 0.91).
Conclusion: The accuracy of prediction of the presence or absence of cleft palate in the presence of cleft lip was high, but the prediction of alveolar clefts was most prone to error. The limitations of such ultrasound predictions should be explained to parents at the time of antenatal counselling.