胎儿NT厚度与染色体异常的关系探讨

Study on the relationship between the fetal nuchal translucency and chromosome abnormalities

目的探讨胎儿颈项透明层(NT)厚度与染色体异常的关系。方法选取2015年10月~2016年9月在首都医科大学附属北京妇产医院行羊水染色体核型分析的4208例孕妇,均在本院或外院经超声检查胎儿NT厚度。分析胎儿NT厚度与胎儿染色体异常的发生情况。结果 4208例行羊水核型分析的病例中,NT增厚胎儿(NT≥2.5mm)218例,发生率为5.18%,其中染色体正常170例,染色体异常48例,异常率22.02%,明显高于无NT增厚胎儿(3990例)中染色体异常(81例)的检出率2.03%,两者比较差异有统计学意义(P<0.05)。此外,胎儿NT增厚组染色体异常类型中,以数目异常比例最高(81.25%)。胎儿NT≥5.0mm染色体异常的发生率明显升高。结论胎儿NT增厚在染色体异常早期筛查中有重要意义,尤其是对于染色体数目异常有较好的预测作用。

Objective： To evaluate the relationship between the fetal nuchal translucency （NT） and chromosome abnormalities. Methods： During October 2015 to September 2016, 4208 cases of pregnant women from Center for Prenatal Diagnosis, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, were all underwent amniotic fluid karyotype analysis and fetal NT thickness by ultrasonic examination. We analyzed the relationship between the fetal NT thickness and the occurrence of chromosomal abnormalities. Results： 218 cases of increased NT thickness （NT ≥2.5mm） were detected in 4208 cases （5.18%） . 48 cases （22.02%） were found chromosomal abnormalities and 170 cases were normal in 218 cases with increased NT thickness. It was significantly higher than chromosomal abnormalities （81 cases） found in non-increased NT thickness （n=3990） , the rate of 2.03%, which was significantly different （P〈0.05） . In addition, the highest percentage of abnormal type was chromosome numerical abnormalities in increased fetus NT thickness group （81.25%） . The incidence of chromosomal abnormalities was obviously increased in the group with fetal NT thickness （NT ≥5.0mm） . Conclusion： Fetal NT thickness is important in the early screening for chromosomal abnormalities, especially for chromosome numerical abnormalities.