超声检查颈项透明层增厚在胎儿染色体异常诊断中的应用价值

The value of nuchal translucency thickness in the fetal chromosome abnormality screening

目的：评价超声检查颈项透明层（nuchal translucency，NT）增厚在胎儿染色体异常筛查中的诊断价值。方法：选择2010年1月至2014年12月在本院行产前超声检查的孕11～13周^＋6孕妇11086例，对胎儿进行超声NT标准化测量，对其中122例NT增厚（NT≥2．5mm）胎儿行染色体核型分析。结果：检出NT≥2．5mm者122例，平均NT厚度（4．5±2．1）mm：122份介入性产前诊断标本染色体核型分析检出染色体异常21例，其中数目异常17例，结构异常4例：发生率最高的前3位依次为：21三体（12例）、染色体臂间倒位（3例）、18三体（2例）。孕妇分娩年龄、胎儿性别、NT厚度的胎儿染色体异常检出率之间存在统计学差异，具体表现为：≥35岁分娩年龄胎儿染色体异常检出率明显高于其他年龄段；女性胎儿染色体异常检出率高于男性；NT厚度≥5．5mm胎儿染色体异常检出率高于NT厚度2．5～3．5mm、3．5～4．5mm组，呈正相关关系（趋势Х^2=15．533，P〈0．001）；Logistic回归分析发现，NT增厚是胎儿染色体异常发生的独立预测因素。结论：在妊娠早期通过超声检查胎儿NT厚度可以作为胎儿染色体异常介入性产前诊断的重要超声筛查指标，NT厚度增加提示胎儿染色体异常的发病风险增加。

Objective To evaluate the value of nuchal translucency （NT） thickness in the fetal chromosome abnormality screening. Methods 11 086 pregnant women received NT measurement in 11 - 13^＋6 weeks at Hainan general hospital from Janual7 2010 to December 2014 were selected in the study. The NT thickness was measured according to guidelines from Fetal Medicine Foundation. 122 fetuses （NT≥2.5 mm） were recruited to accept karyotype analysis. Results 11 086 pregnant WOnlen received NT measurement in 11 - 13^＋6 weeks, in which 122 cases＇ NT are more than or equal to 2.5 mm, with a positive rate of 1.10%. 122 cases of fetal NT thickening are between 2.5 to 12.0 mm, with the average degree at （4.5 ±2.1）mm. 122 invasive prenatal diagnostic specimens chromosome karyotype analysis results showed chromosomal abnormalities in 21 cases （abnormal rate of 17.2%）, the abnormal chromosome number in 17 cases and abnormal structure in 4 cases. The top 3 are trisomy 21 （12 cases, 57.1%）, chromosome pericentric inversion （3 cases, 14.3%）, and trisomy 18 （2 cases, 9.5%）. Fetal chromosonlal abnormalities resulting from different childbirth age, the sex of the fetus, NT thickness showed significant statistical difference （P 〈 0.05）. The concrete manifestation is that fetal chromosomal anomaly detection rate in childbirth by women more than 35 years old age are higher than other age. Female fetal chromosomal anomaly detection rate is higher than the male, and NT thickness of 5mm of fetal chromosomal abnormality rate is significantly higher than the thickness of NT group at 2.5mm- and 3.5mm-. Fetal NT thickening of NT measurements was in significant positive correlation with fetal chromosome abnormal rate （Х^2=15.533, P 〈 0.001）. Logistic regression analysis found that with a higher NT thickness, risk of fetal chromosomal abnormalities would be significantly higher, and thickening of NT could be an independent predictor of fetal chromosome abnormalities. Conclusion In early pregnancy, ultrasound examination of fetal ultrasound screening of NT thickness can be used as an important index of fetal chromosomal abnormality, and interventional diagnosis of prenatal NT thickness increase could pose increased risk of fetal chromosomal abnormalities.