Mandibular Measurements At The 20-Week Anatomy Ultrasound As A Prenatal Predictor Of The Severity Of Pierre-Robin Sequence Associated Respiratory Distress
Raeesa Islam, Erin Anstadt, MD, Lisa Block, MD, Timothy Canavan, MD, Jesse Goldstein, MD.
University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Purpose: Pierre-Robin Sequence (PRS) is defined as micrognathia and glossoptosis leading to upper airway obstruction and possible respiratory distress. Prenatal diagnosis of PRS is key in preparing the delivery team for an airway emergency. Routine 20-week ultrasounds do not screen facial features, which would allow for the evaluation of maxilla-mandibular relationships and mandible size. This study aimed to evaluate 20-week ultrasounds of infants diagnosed with PRS to determine if specific facial measurements could predict PRS disease severity.
Methods: A retrospective review of patients with PRS born between December 2014 and March 2019 was performed. NICU and surgical data were collected. Respiratory and surgical interventions were recorded and scored for severity. Mid-sagittal profile images of the anatomy ultrasound were reviewed for each patient, and 3 parameters were measured to assess for micrognathia: facial-maxillary angle (FMA), facial nasomental angle (FNMA), and alveolar overjet.
Results: 70 PRS patients were reviewed. 40 were excluded for unavailable ultrasounds. Of the remaining 30, 43% had an FMA below 66°, suggesting micrognathia (range: 47-82°, mean: 65.17°). For FNMA, 77% were below 136°, suggesting micrognathia (r: 104-154°, m: 130.9°). Mean alveolar overjet was 3.6mm (r: 2-7mm).
Respiratory outcomes: 12 of 30 patients required no external respiratory support (40%), 11 needed supplemental oxygen by nasal cannula or CPAP (36.7%) and 7 were intubated (23.3%). As respiratory support severity increased, median FMA decreased and alveolar overjet increased, though these differences were not statistically significant. For patients with respiratory independence, median FMA was 68.5° (59.5, 74.75) while the CPAP/NC group had a median FMA of 66° (57, 66) and the intubated group had a median FMA of 65° (52, 66). Alveolar overjet for patients with no respiratory support revealed a median 3.1mm overjet, CPAP/NC patients had 3.2mm, and intubated patients had 3.8mm.
Surgical intervention: 11 patients had no surgical procedures (36.5%), 5 patients underwent supraglottoplasty (16.7%), 13 received mandibular distraction or tongue-lip adhesion (14.3%), and 1 required a tracheostomy (3.3%). There was no statistically significant difference in mean ultrasound measurements between surgical and nonsurgical patients. However, surgical patients tended to have smaller FNMAs and greater overjet compared to nonsurgical patients; median FNMA was 131° versus 132°, and median overjet was 3.2 versus 3.1 mm, respectively.
Five patients required no respiratory or surgical intervention.
Conclusions: In a population of patients with PRS, prenatal facial features on the 20-week ultrasound can be measured. While most patients with PRS at this gestational age had a normal FMA, the majority of patients had an abnormally acute FNMA. Alveolar overjet, previously not described in prenatal ultrasound literature but routinely assessed on neonatal clinical evaluation, is measurable and may have utility in prenatal diagnosis.
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