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.