Two- and three-dimensional sonographic assessment of the fetal face. 2. Analysis of cleft lip, alveolus and palate.

OBJECTIVES: To describe the sonographic appearance of cleft lip with or without cleft palate (CL +/- P) using two-dimensional and three-dimensional (3D) ultrasound imaging. Also, to evaluate the accuracy of ultrasound to delineate with precision the bony extent of facial clefts, i.e. to differentiate clefts limited to the lips, or extending to the alveolus/premaxilla or the secondary palate. METHODS: This was a retrospective study based on the examination of fetuses diagnosed with an isolated CL +/- P. Cases included were either discovered at systematic screening or referred for further investigation. Clefts were characterized by their precise anatomical location and extent. The defect could include a cleft lip (CL), a cleft alveolus (CA), or a cleft of the secondary palate (CSP). RESULTS: We analyzed 96 cases of CL +/- P. The mean gestational age at examination was 28.2 +/- 4.1 weeks. The sonographic appearance of CL, CA, and CSP was depicted. Strict concordance of the sonographic report with the anatomical defect was present in 84 cases (87.5%). In eight cases, the severity of the cleft was underestimated: three cases of CA, four of CA + CSP and one of CSP were missed. In four cases, the cleft was overestimated as CA was incorrectly suspected. CONCLUSIONS: Systematic screening with sonography to detect prenatally CL +/- P requires the imaging of at least the mid-sagittal and the anterior coronal 'nose-mouth' views. Once the presence of a facial cleft is suspected, the three reference orthogonal planes are imaged in order to characterize the anatomical defect, and for each plane, the serial scans are thoroughly examined. This protocol allows precise delineation of the defect. Inclusion of 3D and 4D ultrasound imaging in the examination protocol allows easier and more rapid screening and more precise evaluation of the different cleft constituents.