昆明地区妊娠早期正常单胎胎儿颈部透明层厚度的分布及参考值范围

Distribution and normal reference range of fetal nuchal translucency thickness in Kunming pregnantwomen in the first trimester

目的调查昆明地区妊娠早期正常单胎胎儿颈部透明层（NT）厚度的分布情况，制定本地区NT厚度的参考值范围。方法以2009--2010年在昆明医学院第一附属医院就诊的妊娠早期（孕11～13周^＋6）单胎孕妇共1790例为观察对象，参照英国胎儿基金会（FMF）的标准超声测量胎儿头臀径（CRL）及NT厚度，并随访妊娠结局，对确认为正常胎儿的上述测量值通过简单线性回归分析CRL与NT厚度的相关性，制定本地区妊娠早期正常单胎胎儿NT厚度的参考值范围。结果最终纳入本研究的1790例正常单胎胎儿的CRL均数为（59．6±9．2）mm，中位数为58．3mm，NT厚度均数为（1.7±0．5）mm，中位数为1．7mm。不同CRL范围内NT厚度的参考值范围不同，胎儿CRL在45．0～54．9mm、55.0～64.9mm、65．0～74.9mm、75.0～84．0mm范围时，相应的NT厚度测量值第5～95百分位数分别为1．0—2．0mm、103～2．5mm、1.5～2．7mm、1.5～2．9mm，中位数分别为1．4、1．7、2．0、2．0mm。胎儿NT厚度测量值与孕妇年龄无显著相关性（P〉0．05）；男胎NT厚度测量值的均数为（1．84-1．1）mm，女胎为（1．74-0．6）mm，两者比较，差异有统计学意义（P=0．001）。结论本研究初步制定出昆明地区妊娠早期正常单胎胎儿不同CRL相对应的NT厚度参考值范围，为产前筛查的进一步实施提供了参考依据。

Objective To establish the normal reference range of fetal nuchal translucency （NT） thickness in Kunming Chinese pregnant women in the first trimester. Methods The study samples comprised of 1790 Kunming pregnant women who attended antenatal visit in the first trimester in the First Affiliated Hospital of Kunming Medical University. The general information including maternal date of birth, past pregnant history and other related conditions were recorded. The crown rump length （CRL） and NT thickness at 11 -13^＋6 gestational weeks were measured according to guidelines from Fetal Medicine Foundation （FMF）. Results The total 1790 of normal fetuses was recruited for final analysis. The mean and median values of CRL were （ 59.6 ~ 9.2 ） mm and 58.3 ram, respectively. The mean and median values of NT thickness were （ 1.7±0. 5 ） mm and 1.7 ram, respectively. While the CRL were at between 45.0 - 54.9 ram, 55.0-64.9 ram, 65.0 -74.9 mm and 75.0-84.0 mm, the corresponding values of NT thickness were 1.0 ram, 1.3 mm, 1.5 mm, 1.5 mm at the 5th percentile and 2. 0 mm, 2. 5 mm, 2. 7 ram, 2. 9 mm at the 95th percentile, respectively, and the corresponding medial values of NT thickness were 1.4 ram, 1.7 ram, 2. 0 ram, 2. 0 ram, respectively. The NT thickness had no relationship with maternal age （ P 〉 0. 05 ）. The mean value of NT thickness was （ 1.8±1.1 ）mm in male fetuses. The mean value of NT thickness was （ 1.7±0. 6） mm in female fetuses. The NT thickness in male fetuses was significantly thicker than that of females （ P = 0. 001 ）. Conclusion The present study established a reference range of normal fetal NT thickness corresponding with CRL in early pregnancy with reliable FMF quality control.