3D Ultrasound Evaluation of the Fetal Outer Ear: Novel Biometry Ratio and Comparison of Different Surface Display Modes

Artificial intelligence-based diagnosis in fetal pathology using external ear shapes

OBJECTIVE

Here we trained an automatic phenotype assessment tool to recognize syndromic ears in two syndromes in fetuses-=CHARGE and Mandibulo-Facial Dysostosis Guion Almeida type (MFDGA)-versus controls.

METHOD

We trained an automatic model on all profile pictures of children diagnosed with genetically confirmed MFDGA and CHARGE syndromes, and a cohort of control patients, collected from 1981 to 2023 in Necker Hospital (Paris) with a visible external ear. The model consisted in extracting landmarks from photographs of external ears, in applying geometric morphometry methods, and in a classification step using machine learning. The approach was then tested on photographs of two groups of fetuses: controls and fetuses with CHARGE and MFDGA syndromes.

RESULTS

The training set contained a total of 1489 ear photographs from 526 children. The validation set contained a total of 51 ear photographs from 51 fetuses. The overall accuracy was 72.6% (58.3%-84.1%, p < 0.001), and 76.4%, 74.9%, and 86.2% respectively for CHARGE, control and MFDGA fetuses. The area under the curves were 86.8%, 87.5%, and 90.3% respectively for CHARGE, controls, and MFDGA fetuses.

CONCLUSION

We report the first automatic fetal ear phenotyping model, with satisfactory classification performances. Further validations are required before using this approach as a diagnostic tool.

Fetal Phenotype of CHARGE Syndrome with a Molecular Confirmation: A Series of 13 Cases

INTRODUCTION

CHARGE syndrome is an autosomal dominant genetic disorder with known pattern of features. The aim of the study was to present the fetal features of CHARGE syndrome to gain awareness that the antenatal characteristics can be very nonspecific.

CASE PRESENTATION

This was a retrospective study of 13 cases with CHARGE syndrome diagnosed by prenatal or postnatal genetic testing and physical examination. Two (15.4%; 2/13) had normal ultrasound scans during pregnancy. One (7.7%; 1/13) with first-trimester cystic hygroma presented intrauterine fetal demise at 16 weeks gestation. The remaining 10 (76.9%; 10/13) cases had abnormal ultrasound features in utero; among these, 1 had an increased nuchal translucency in the first trimester, 5 had second-trimester abnormal ultrasounds including micrognathia, cardiac defects, and facial defects, and 4 third-trimester abnormal ultrasounds including micrognathia, isolated fetal growth restriction, and polyhydramnios. Among the 11 cases with abnormal prenatal ultrasound scans, no fetus could reach the diagnostic criteria of CHARGE syndrome if only based on the results of ultrasound. However, the diagnosis was made in all cases when CHD7 defects were detected.

DISCUSSION/CONCLUSION

The CHARGE syndrome presents non-specific abnormal ultrasound markers in utero. Exome sequencing in the genetic workup will aid in prenatal diagnosis of this syndrome.

[Antenatal ear examination: When, how and why?]

Antenatal ear examination is an integral part of the thorough examination of the fetal face. The discovery of an anomaly, whether it is made by chance or during a complementary in-depth examination, leads the practitioner to determine its isolated or associated character, in order to characterise its possible belonging to a syndromic entity. In this context, the realization of genetic analysis more precise and wider allowing a return of the results in a time compatible with an evolutive pregnancy, gives to the geneticist a central role in the management of these couples. The main challenge lies in obtaining a set of concordant clinical and biological clues, enabling the genetic results identified to be interpreted correctly, the optimised functioning of the ultrasound practitioner - geneticist duo is therefore fundamental. This results in a complex information to deliver, in the fact that the clinical translation of an ear anomaly in antenatal can go from an isolated aesthetic anomaly to a genetic syndrome with neurodevelopmental disorder. The objective of this work is to describe, from a methodological analysis of antenatal ears, the accessible malformative entities, isolated or associated, and to discuss the problems in the need or not to propose their screening.