Two- and three-dimensional sonographic assessment of the fetal face. 1. A systematic analysis of the normal face.

OBJECTIVES

To detail fetal facial examination in utero using ultrasound, to distinguish between requirements for routine screening and those for precise analysis of fetal facial features, and to assess the use of three-dimensional (3D) ultrasound imaging in fetal facial examination.

METHODS

This was a retrospective study, based on the examination of approximately 10,500 fetuses. The usual age at screening ultrasound examination was 22 +/- 1 gestational weeks.

RESULTS

The sonographic anatomy of the normal fetal face was depicted, and the relevance of the three reference scanning planes, sagittal, coronal and axial, was specified.

CONCLUSIONS

At routine screening using two-dimensional sonography, at least two selected views must be imaged: the mid-sagittal plane (search for facial dysmorphology) and the anterior 'nose-mouth' coronal plane (search for disruption in lip continuity or deformation of the narinal bend). Precise analysis of fetal facial anomalies requires visualization and thorough step-by-step analysis in the three planes. The difference between routine screening and precise facial features' analysis has been greatly decreased since 3D and 4D sonography have become readily available. Using this modality, after surface analysis of the fetal face, the three reference planes are simultaneously imaged, using the multiplanar modality, and detailed. 3D/4D ultrasound imaging allows easier, more rapid screening and more precise evaluation of the different facial features.