Ultrasonographic study of fetal mandibular markers during the first trimester in a Chinese population

Evaluating Prenatal Diagnostic Imaging for Micrognathia: A Systematic Review and Meta-Analysis

OBJECTIVE

Studies evaluating the ability to diagnose and accurately predict the severity of micrognathia prenatally have yielded inconsistent results. This review aimed to evaluate reliability of prenatal diagnostic imaging in the diagnosis and characterization of micrognathia.

DESIGN

Systematic review and meta-analysis.

SETTING

Studies with a prenatal diagnosis of micrognathia via ultrasound with a confirmatory postnatal examination were included. Prenatal severity was defined with and without mandibular measurements. Extent of airway obstruction at birth was defined by level of intervention required. Meta-analyses of proportions and relative risk were performed.

PATIENTS

A total of 16 studies with 2753 neonates were included.

MAIN OUTCOME MEASURES

Primary outcome was the efficacy of characterizing the degree of micrognathia on prenatal imaging as it relates to respiratory obstruction at birth. Secondary outcome was the accuracy of prenatal diagnosis with the utilization of mandibular measurements versus without.

RESULTS

Performing meta-analysis of proportions, the proportion of missed prenatal diagnoses of micrognathia made without mandibular measurements was 11.62% (95%CI 2.58-25.94). Utilizing mandibular measurements, the proportion of cases missed were statistically lower (0.20% [95%CI 0.00-0.70]). Patients determined to have severe micrognathia by prenatal imaging did not have a statistically significant increase in risk for more severe respiratory obstruction at birth (RR 3.13 [95%CI 0.59-16.55], P = .180).

CONCLUSION

The proportion micrognathia cases missed when prenatal diagnosis was made without mandibular measurements was over 1 in 10, with mandibular measures improving accuracy. This study highlights the need for a uniform objective criterion to improve prenatal diagnosis and planning for postnatal care.

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.

Ultrasound measurements of fetal facial profile markers and their associations with congenital malformations during early pregnancy

BACKGROUND

Fetal facial profile could be measured during the early pregnancy. Its abnormalities might be associated with certain congenital malformations. We aimed to study the associations between fetal facial profile measurements with crown-rump length and congenital malformations (cleft lip and palate, micrognathia, and open spina bifida) during early pregnancy.

METHODS

We performed a prospective cross-sectional study between June 2019 and April 2022. Pregnant women at a gestational age between 11-13+ 6 weeks were enrolled. Two sonographers performed fetal facial profile measurements independently. The associations between these measurements with crown-rump length and congenital malformations were evaluated.

RESULTS

There were 406 and 25 fetuses without or with congenital malformations, respectively. Two sonographers showed satisfactory inter- and intra-observer agreements and reproducibility. The maxillary gap was only observed in 7.6% of normal fetuses, whereas all cleft lip and palate fetuses had a maxillary gap ≥ 0.8 mm. The crown-rump length was negatively correlated with frontomaxillary facial angle, inferior facial angle, and profile line distance but positively correlated with maxilla-nasion-mandible angle, facial maxillary angle, frontal space distance, and palatine maxillary diameter. These measurements showed various significant changes with different congenital malformations.

CONCLUSIONS

Measurements of fetal facial profile in early pregnancy were feasible with satisfactory reproducibility. These measurements correlated with crown-rump length and showed significant differences with certain fetal congenital malformations.

Prenatal diagnosis of micrognathia: a systematic review

Purpose

This systematic review aimed to analyze the characteristics of different diagnostic techniques for micrognathia, summarize the consistent diagnostic criteria of each technique, and provide a simple and convenient prenatal diagnosis strategy for micrognathia.

Methods

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the search was undertaken in three international databases (PubMed, Scopus, and Web of Science). The three reviewers assessed all papers and extracted the following variables: author's name and year of publication, country, study design, number of participants, gestational age, equipment for prenatal examination, biometric parameters related to micrognathia, main results.

Results

A total of 25 articles included in the analysis. Nineteen articles described cross-sectional studies (76 percent), 4 (16 percent) were case-control studies, and 2 (8 percent) were cohort studies. Fifteen studies (60 percent) had a prospective design, 9 (36 percent) had a retrospective design, and one (4 percent) had both prospective and retrospective design. Thirty-two percent of the studies (n = 8) were performed in USA, and the remaining studies were performed in China (n = 4), Israel (n = 3), Netherlands (n = 3), UK (n = 1), France (n = 1), Italy (n = 1), Belgium(n = 1), Germany (n = 1), Spain (n = 1), and Austria (n = 1). The prenatal diagnosis of micrognathia can be performed as early as possible in the first trimester, while the second and third trimester of pregnancy were the main prenatal diagnosis period. The articles that were included in the qualitative synthesis describe 30 biometric parameters related to the mandible.

Conclusion

Of the 30 biometric parameters related to the mandible, 15 can obtain the simple and convenient diagnostic criteria or warning value for micrognathia. Based on these diagnostic criteria or warning value, clinicians can quickly make a preliminary judgment on facial deformities, to carry out cytologic examination to further clarify the diagnosis of micrognathia.