First trimester sonographic diagnosis of orofacial defects. Review of literature

Prenatal Diagnosis of Fetal Micrognathia at 11-20 Weeks of Gestation: A Prospective Observation Study

OBJECTIVE

To prospectively evaluate the prognosis of fetuses diagnosed with micrognathia using prenatal ultrasound screening.

METHODS

Between January 2019 and December 2022, a normal range of IFA to evaluate the facial profile in fetuses with micrognathia in a Chinese population between 11 and 20 gestational weeks was established, and the pregnancy outcomes of fetal micrognathia were described. The medical records of these pregnancies were collected, including family history, maternal demographics, sonographic findings, genetic testing results, and pregnancy outcomes.

RESULTS

Ultrasound identified 25 patients with fetal micrognathia, with a mean IFA value of 43.6°. All cases of isolated fetal micrognathia in the initial scans were non-isolated in the following scans. A total of 78.9% (15/19) cases had a genetic cause confirmed, including 12 with chromosomal abnormalities and 3 with monogenic disorders. Monogenic disorders were all known causes of micrognathia, including two cases of campomelic dysplasia affected by SOX9 mutations and one case of mandibulofacial dysostosis with an EFTUD2 mutation. In the end, 19 cases were terminated, 1 live birth was diagnosed as Pierre Robin syndrome, and 5 cases were lost to follow-up.

CONCLUSION

IFA is a useful indicator and three-dimensional ultrasound is a significant support technique for fetal micrognathia prenatal diagnosis. Repeat ultrasound monitoring and genetic testing are crucial, with CMA recommended and Whole exome sequencing performed when normal arrays are reported. Isolated fetal micrognathia may be an early manifestation of monogenic disorders.

First Trimester Tricuspid Regurgitation: Clinical Significance

Tricuspid regurgitation is a cardiac valvular anomaly that consists of the return of blood to the right atrium during systole due to incomplete valve closure. This structure can be visualized on ultrasound between 11 and 14 weeks of gestation in most cases. Despite being a common finding, even in healthy fetuses, the presence of tricuspid regurgitation may be associated with chromosomal and structural abnormalities. The evaluation of tricuspid flow and the presence of regurgitation on first-trimester ultrasound has shown promising results regarding its role in the early detection of aneuploidies, congenital heart defects, and other adverse perinatal outcomes. This review article aims to demonstrate the importance of tricuspid regurgitation as a secondary marker, and consequently, significant benefits of its early detection when added to the combined first-trimester screening. Its value will be discussed, namely its sensitivity and specificity, alone and together with other current markers in the fetal assessment performed in the first-trimester ultrasound.

Fetal micrognathia in the first trimester: An ominous finding even after a normal array

OBJECTIVE

To evaluate the prognosis of fetuses with a prenatal diagnosis of micrognathia in the first trimester.

STUDY DESIGN

Over a 3-year period, patients with fetal micrognathia were detected at the time of nuchal translucency screening. The medical records of these pregnancies were reviewed, including maternal demographics, sonographic findings, genetic testing results and pregnancy outcomes.

RESULTS

Forty-three cases of first-trimester micrognathia were included in this study. Chromosomal abnormalities were detected in seven cases. Of the fetuses with a normal array, further investigation of monogenic disorders with whole-exome sequencing was undertaken in 13 cases. Monogenic syndromes were identified in eight cases, including six with de-novo dominant alleles and two with recessive conditions. Whole-exome sequencing was refused in 23 cases; among these, other additional anomalies were found on anatomic ultrasound in 10 cases.

CONCLUSION

This study demonstrated that caution should be adopted when finding an apparently isolated micrognathia in early gestation, even with a normal array. A diagnosis of genetic syndrome or multiple anomalies on subsequent scans is most likely, and will affect the final prognosis.