广东省顺德地区6 503例孕中期羊水染色体核型结果分析

目的 探讨羊水细胞异常核型发生的频率、类型与不同产前诊断指征之间的关系,评估羊水穿刺术诊断染色体疾病的临床价值。方法 选取2009年7月～2018年7月在广东医科大学顺德妇女儿童医院产前诊断中心具有产前诊断指征的孕妇6 503例,进行羊水穿刺,胎儿羊水细胞染色体核型分析。结果①6 503例羊水细胞中,检出染色体异常核型358例,异常率5.51%。染色体数目异常264例,其中21三体128例,18三体51例,13三体20例,性染色体数目异常65例; 染色体的结构异常66例; 嵌合体28例。各产前诊断指征中,染色体异常检出率分别为3.34%,3.15%,61.95%,17.22%,37.14%,5.60%和0.62%,经χ²检验发现,高龄组与血清学筛查高风险组,高龄组与不良孕产史组,血清学筛查高风险组与不良孕产史组,差异均无统计学意义(χ2=0.147～2.279,均P>0.05); 其余各组之间两两比较,差异均有统计学意义(χ2=7.411～997.801,均P<0.01)。②2 456例高龄孕妇中,年龄35～39岁组与年龄≥40岁组胎儿染色体异常检出率分别为2.70%和5.63%,两者比较,差异有统计学意义(χ2=11.059,P<0.01)。③无创产前基因筛查(NIPT)对21三体、18三体和13三体的检测准确度分别为80.28%,75.86%和44.00%,对性染色体异常的检测准确度为55.17%,对其他染色体异常的检测准确度为22.73%。结论 ①对具有明确产前诊断指征的孕妇行羊膜腔穿刺术,进行羊水细胞染色体核型分析非常重要,可有效地检出染色体异常胎儿,避免其出生,提高人口素质。②高龄孕妇,尤其是≥40岁的高龄孕妇,进行产前诊断非常必要。③NIPT对筛查胎儿染色体疾病准确率较高,但只是筛查手段,不能完全代替羊水细胞核型分析。

Analysis of Chromosome Karyotype Results of 6 503 Cases ofAmniotic Fluid in Shunde Area of Guangdong Province

Objective To explore the relationship between the frequency and type of abnormal karyotypes in amniotic fluid cells and different prenatal diagnostic indications,and evaluate the clinical value of amniocentesis in the diagnosis of chromosomal diseases.Methods From July 2009 to July 2018,6 503 pregnant women with prenatal diagnosis indications in the Prenatal Diagnosis Center of Shunde Women and Children Hospital of Guangdong Medical University were selected for amniocentesis and karyotype analysis of fetal amniotic fluid cells.Results ①In 6 503 cases of amniotic fluid cells,358 cases ofchromosomalabnormalities were detected,and the abnormal rate was 5.51%.Therewere 264 cases of abnormal chromosome number,of which were 128 cases of 21 trisomy,51 cases of 18 trisomy,20 cases of trisomy 13 and 65 cases of abnormal chromosome number,66 cases of abnormal chromosome structure and 28 caces of chimera.In the prenatal diagnosis indications,the detection rates of chromosomal abnormalities were 3.34%,3.15%,61.95%,17.22%,37.14%,5.60% and 0.62%,respectively.The χ² test found that there was no significant difference between the elderly group and the serological screening high risk group,the elderly group and the poor maternal history group,the serological screening high risk group and the poor maternal history group(χ²=0.147～2.279, all P>0.05).The other groups were compared between the two groups and the difference was statistically significant(χ²=7.411～997.801,all P<0.01).②Among the 2 456 pregnant women,the detection rates of fetal chromosomal abnormalities in the age group of 35～39 years old and age ≥ 40 years old were 2.70% and 5.63%,respectively,and the difference was statistically significant(χ²=11.059,P<0.01).③The detection accuracy of NIPT for trisomy 21,trisomy 18 and trisomy 13 were 80.28%,75.86% and 44.00%,respectively.The accuracy of detection for sex chromosome abnormalities was 55.17%,and the accuracy of detection for other chromosomal abnormalities was 22.73%.Conclusion ①Amniocentesis for pregnant women with high risk,and karyotype analysis of amniotic fluidcells can effectively detect chromosomal abnormalities of the fetus,avoid birth and improve the population quality.②Older pregnant women,especially thoseaged 40 or older,are necessary for prenatal diagnosis.③NIPT has a high accuracy rate for screening fetal chromosomal diseases,but it is only a screeningmethod and cannot completely replace the amniotic fluid karyotype analysis.