OC23.03: Abnormal craniofacial integrity assessed by the novel maxilla‐mandibula‐nasion angle in aneuploid fetuses

To scrutinise the pattern of craniofacial anomalies assessed by the novel maxilla-mandibula-nasion angle in aneuploid 2nd trimester fetuses. The MMN angle is defined by the angle between the fetal profile line (FP line) and the mandibulo-maxillary line. This retrospective study included midsagittal 2D images and 3D volume data sets of 137 fetuses with confirmed aneuploidy. The results for MMN were compared to those retrieved from normal matched controls. A total of 134/137 eligible cases were enrolled in this study. The mean GA was 24.3 weeks (range 14.0–26.1 wks). The mean MMN for Trisomy 21 cases (n = 97) was significantly more acute than in normal (14.9°; range 10.2°–22.3° vs. 20.6°; range 17.3°–23.7°; p < 0.0001). In fetuses with Trisomy 18 (n = 25) the mean MMN was 22.9° (range 17.1–28.1°) and in cases with Trisomy 13 (n = 12) the mean MMN was 20.3° (range 16.0–26.9) and differed not significantly from controls. This finding might be in part explained by the presence of additional craniofacial abnormalities such as micrognathia or facial clefting. However, forehead anomalies (displayed by an abnormal FP line) were frequently observed in Trisomy 13 and 18 (27/37 cases). Supporting information can be found in the online version of this abstract Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.