Zhengzhou University Third Hospital, and Henan Province Women and Children's Hospital, Zhengzhou, Henan, China.
J Obstet Gynaecol Res. 2022 Feb;48(2):333-339. doi: 10.1111/jog.15121. Epub 2021 Dec 2.
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.
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.
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.
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.
在中国人群中，为 11-13+6 孕周的低危单胎妊娠建立胎儿下颌标志的参考范围。
在 11-13+6 孕周时测量下颌的下面角（IFA）、横向、前后径和下颌长度。探讨了这 7 例胎儿下颌超声标志在检测小下颌中的应用。
在 11-13+6 孕周的健康胎儿中，下颌的横向（Y=-15.615+1.987X，r=0.718，p<0.001）和前后径（Y=-8.557+1.101X，r=0.581，p<0.001）与胎龄呈线性相关；下颌前后径与横向直径的平均比值随胎龄的增加而降低（Y=0.603-0.003X，r=0.018，p=0.755）；头臀长与下颌长度呈正相关（下颌长度=0.861+0.137*头臀长；r=0.723，p<0.001）；头臀长与 IFA 呈正相关（r=0.234，p<0.05）。参考范围为：下颌前后径与横向直径的平均比值为 0.56；下颌平均长度为 9.05mm；IFA 中位数为 66.5°。这 7 例胎儿小下颌的下颌标志值均超出正常范围。
在早孕期超声筛查中评估胎儿下颌标志有助于小下颌的早期发现和诊断。我们建议在常规测量颈项透明层厚度的正中矢状面上，对手动测量下颌的主观印象进行评估，然后在疑似病例中，在正中矢状面和轴向面上进行有针对性的客观测量。
