Fetal frontomaxillary facial angle between 11 and 13 + 6 weeks of gestation in a Brazilian population: influence of different races

Abstract

Objective: To evaluate the influence of different races over the measurement of the frontomaxillary facial angle between 11 and 13 + 6 weeks of pregnancy in a Brazilian population.Methods: A cross-sectional study was conducted with 332 healthy pregnant women, with a crown-rump length (CRL) between 47 and 84 mm. Such measurements were taken abdominally, using the mid-sagittal plane, and the angle was measured by tracing a line over the palate and a line from the anterosuperior maxillary angle all the way to the external part of the forehead. As for the reference intervals, a simple linear regression between the frontomaxillary facial angle and the CRL was used, as well as Pearson’s correlation coefficient (r). To evaluate the difference between races, a variance analysis was used (ANOVA). To calculate reproducibility, the intraclass correlation coefficient (ICC) was used.Results: The means for the fetal frontomaxillary facial angle in white, black and mixed races were 81.8 ± 6.6; 82.2 ± 6.1 and 81.4 ± 6.2 mm, respectively. There was no statistical difference between races (p = 0.713). A decreasing correlation between the frontomaxillary facial angle and the CRL was observed for the black (r = −0.450) and mixed (r = −0.212) races. Excellent intraobserver reproducibility was observed, as well as a satisfactory interobserver reproducibility, with ICC of 0.858 and 0.605, respectively.Conclusion: There were no significative statistical differences in the measurement of the fetal frontomaxillary facial angle between 11 and 13 + 6 weeks of pregnancy in the different races in a Brazilian population.