孕20～28周胎儿鼻前皮肤正常值范围的建立

目的：建立中国南方人群孕20～28周胎儿鼻前皮肤（ PT）厚度的正常值范围。方法2013年7月至2014年12月，对参加广州市妇女儿童医疗中心中孕期（孕20～28周）超声结构筛查的胎儿进行PT测量，产后3个月进行随访，剔除胎儿结构异常，妊娠合并症及胎儿出生后明显结构缺陷的病例，建立孕20～28周胎儿PT值正常值曲线模型。结果在440例正常胎儿病例中，孕妇中位年龄28岁（21～42岁），中位孕周23周（20～28周），胎儿PT中位值4．0mm（2．9～7．2mm）。随着孕周增加， PT从20周的3．8mm增加到孕28周的5．4mm。统计分析，胎儿PT值与孕周呈线性正相关，线性回归方程：PT＝0．285＋0．17× GA（R2＝0．194，P＝0．000）。结论孕20～28周，胎儿PT随孕周增加而增加，并与孕周呈直线相关。

Normal range of fetal prenasal thickness between 20-28 weeks of gestation

Objective To establish normal range of fetal prenasal thickness ( PT) between 20 to 28 weeks of gestation in southern Chinese population.Methods From July 2013 to December 2014, the fetuses at 20-28 weeks of gestation were enrolled in this study and their PT was measured .Follow-up was conducted 3 months after delivery .Cases of structural defects , pregnant complications and obvious structural defects found after birth were excluded .Normal PT range was established for fetus at 20-28 weeks of gestation .Results Of 440 normal fetuses, the median age of lying-in women was 28 years old (21-42 years), median gestation was 23 weeks, and the median PT value was 4.0mm (2.9-7.2mm).With the increasing of gestational week , PT increased from 3.8mm at 20 weeks to 5.4mm at 28 weeks (R2 =0.194, P=0.000).PT value was positively correlated with gestational week .Equation of linear regression was PT =0.285+0.17 ×GA. Conclusion PT value increases with the increasing of gestational week at 20 to 28 weeks, and there is a linear correlation between PT value and gestational week .