{Reference Type}: Journal Article
{Title}: Ultrasonographic study of fetal mandibular markers during the first trimester in a Chinese population.
{Author}: Li H;Zhu Z;
{Journal}: J Obstet Gynaecol Res
{Volume}: 0
{Issue}: 0
{Year}: Dec 2021 2
{Factor}: 1.697
{DOI}: 10.1111/jog.15121
{Abstract}: <B>OBJECTIVE: </B>To establish reference ranges for fetal mandibular markers in low-risk singleton pregnancies between 11 and 13 + 6 weeks of gestation in a Chinese population.<BR><B>METHODS: </B>The inferior facial angle (IFA), transverse, and anteroposterior diameters of the mandible, and mandibular length were measured at 11-13 + 6 weeks of gestation. The utility of these sonographic markers for detecting micrognathia was explored in seven fetuses.<BR><B>RESULTS: </B>In healthy fetuses at 11-13 + 6 weeks, there were linear correlations between gestational age and the transverse (Y = -15.615 + 1.987X, r = 0.718, p < 0.001) and anteroposterior (Y = -8.557 + 1.101X, r = 0.581, p < 0.001) diameters of the mandible; mean ratio of the anteroposterior: transverse diameters of the mandible decreased with gestational age (Y = 0.603-0.003X, r = 0.018, p = 0.755); there was a positive correlation between crown rump length and mandibular length (mandible length = 0.861 + 0.137*crown rump length; r = 0.723, p < 0.001); and there was a positive correlation between crown rump length and IFA (r = 0.234, p < 0.05). Reference ranges were: mean ratio of anteroposterior diameter: transverse diameter of the mandible 0.56; mean mandibular length 9.05 mm; and median IFA 66.5°. The values for these mandibular markers in seven cases of fetal micrognathia were outside the normal range.<BR><B>CONCLUSIONS: </B>Evaluations of fetal mandibular markers during first trimester ultrasound screening may contribute to the early detection and diagnosis of micrognathia. We recommend obtaining a subjective impression of the mandible on the mid-sagittal view routinely used to measured nuchal translucency, followed by targeted objective measurements on the mid-sagittal and axial views in suspected cases.