Craniofacial variability index in utero: a three-dimensional ultrasound study

This study was undertaken to develop a craniofacial pattern profile analysis by three-dimensional (3D) ultrasound and to introduce a craniofacial variability index (CVI) which can assist in the evaluation of fetal facial anatomy.

Serial 3D sonographic measurements of 16 different fetal craniofacial parameters were performed at 18-34 weeks of gestation in 126 normal singleton pregnancies. In another six pregnancies complicated by fetal abnormality, a single 3D recording was obtained. The 16 measurements cover various aspects of the facial anatomy, such as width, depth and height. For each parameter, regression analysis was performed to calculate gestational age-specific Z-scores and normal limits for the CVI (the latter quantifies the variability between the 16 Z-scores).

The 95th percentile of normal CVI data increased from 1.08 at 18 weeks to 1.27 at 34 weeks of gestation. The CVI was situated above the 95th percentile in three out of six fetuses with abnormalities. In abnormal subjects, 2-8 of 16 parameters showed abnormal values.

Craniofacial pattern profile analysis and the CVI may aid in the evaluation of fetal facial anatomy. They could be a valuable tool in syndrome delineation and for distinguishing between normal and abnormal craniofacial development.