Ultrasonographic Study Of Fetal Facial Profile Markers During The First Trimester

ObjectiveTo investigate the feasibility and repeatability of fetal frontomaxillary facial（FMF）angle,maxilla nasion mandibular（MNM）angle,facial-maxillary angle（FMA）,inferior facial angle（IFA）,frontal space（FS）distance,fetal profile line（PL）distance,palatine maxillary diameter（PMD）,maxillary gap（MG）in early pregnancy.To establish the normal reference range in the local population and investigate its correlation with crown-rump length（CRL）.To explore the sensitivity and specificity of these facial markers in the diagnosis of fetal cleft lip and palate,micrognathia,and open spina bifida.Materials and MethodsWe performed a prospective cross-sectional study between June 2019 and April2022.Pregnant women at a gestational age between 11-13⁺⁶weeks were enrolled.Two sonographers performed fetal facial profile measurements independently,including frontomaxillary facial angle,maxilla-nasion-mandible angle,facial maxillary angle,inferior facial angle,frontal space distance,profile line distance,palatine maxillary diameter,and maxillary gap.The associations between these measurements with crown-rump length and congenital malformations were evaluated.Results406 cases were normal group and 25 cases were abnormal group.Among these facial markers,there is good consistency and reproducibility within and between observers.In the normal group,An average of frontomaxillary facial（FMF）angle,maxilla nasion mandibular（MNM）angle,facial-maxillary angle（FMA）,inferior facial angle（IFA）,frontal space（FS）distance,fetal profile line（PL）distance,palatine maxillary diameter（PMD）were 86.4±3.1°、7.8±2.1°、64.3±3.8°、67.1±3.5°、-1.7±1.6mm、3.4±0.6 mm、6.6±0.9mm mm.Maxillary gap was present in 7.6%of normal fetuses,while maxillary gap（GM）was≥0.8 mm in all fetuses with cleft lip and palate.CRL was negatively correlated with facial-maxillary angle（FMF）,inferior facial angle（IFA）and fetal profile line（PL）distance,but positively correlated with Maxilla nasion mandibular（MNM）,facial-maxillary angle（FMA）,frontal space（FS）distance and palatine-maxillary diameter（PMD）.These facial markers were significantly different in the fetal congenital malformations（cleft lip and palate,micrognathia,open spina bifida）.ConclusionThe measurement of fetal facial markers in early pregnancy is feasible and reproducible.These facial markers were significantly associated with crown-rump length（CRL）and differed significantly in fetal congenital malformations（cleft lip and palate,micrognathia,and open spina bifida）.