Biostatistical evaluation of the effectiveness of fetal ultrasound diagnostics with application of new uncertainty factor and difficulty factor in cases of craniofacial malformations-gray zone in biostatistics for imaging procedures.

Background: The craniofacial malformations occur less frequently, with a prevalence rate of approximately 0.1%. Our aim is to investigate the effectiveness of prenatal ultrasound in the detection of the craniofacial abnormalities.

Methods: In our study, we have processed the prenatal sonographic and postnatal clinical and fetopathological data of 242 anatomical deviations of 218 fetuses with craniofacial malformations over a 12-year period. The patients were divided into three groups: Group I, Totally Recognized; Group II, Partially Recognized; Group III, Not Recognized. To characterize the diagnostics of disorders we developed the Uncertainty Factor F (U) = P (Partially Recognized)/[P (Partially Recognized) + T (Totally Recognized)] and Difficulty factor F (D) = N (Not Recognized)/[P (Partially Recognized) + T (Totally Recognized)].

Results: Prenatal ultrasound diagnosis of fetuses with facial and neck malformations completely coincided in 71/218 cases (32.6%) with postnatal/fetopathological findings. In 31/218 cases (14.2%) the detection was only partial, while in 116/218 cases no craniofacial malformations were diagnosed prenatally (53.2%). The Difficulty Factor was high or very high in almost each disorder group, with a cumulative score of 1.28. The Uncertainty Factor cumulative score was 0.32.

Conclusions: The effectiveness of the detection of the facial and neck malformations was low (29.75%). The Uncertainty Factor F (U) and Difficulty Factor F (D) parameters, which characterized the difficulties of the prenatal ultrasound examination well.