羊水细胞学检查在产前诊断中的应用

目的：分析产前诊断的高危孕妇羊水细胞染色体核型，了解孕中期异常核型出现的频率，类型及与各种产前诊断指征之间的关系。方法：130例有产前论断孕妇（2例为双胎妊娠）在妊娠17－27周时行羊膜腔穿刺术，抽羊水行羊水细胞培养查染色体核型。结果：羊水细胞培养成功并进行核型分析的为126例，成功率为95．4％；妊17－20周与妊20－27周的羊水培养成功率未见显著差异，分别95．9％（71／74），94．8％（55／58），P＞0．05；发现异常核型10例，异常检出率为7．8％（10／126）；三体为主要的染色体异常，占异常核型的40％（4／10），其中21三体占30％（3／10），性染色体数目异常及平衡易位各1例，4例INV9；畸胎为指征的异常核型检出率高达33．3％（2／6）；发现1例单卵双胎妊娠两胎均为21三体儿；高龄为指征占成功产前诊断的46．3％（60／126），检出异常核型3例，检出率5％（3／60）。结论：在有产前诊断指征的孕妇中，胎儿染色体异常核型的发生率为7．8％，三本仍是妊娠中期主要的异常核型，结合B超筛查及定位的羊膜腔穿刺术在产前诊断仍占有不可代替的重要作用。

Analysis of chromosomal karyotypes in 126 fetal amniotic fluid cells for prenatal diagnosis

To analyze the fetal chromosomal karyotypes from the amniotic fluid cells obtained by amniocentesis during the second trimesters,and investigate the types of chromosomal abnormalities,as well as the relationship between the abnormal karyotypes and the indications of prenatal diagnosis.Methods:Amniocenteses were performed in 130 pregnant women with different indications for prenatal diagnosis during the 17 to 27 gestational weeks(two cases with twin pregnancy),and 126 fetal chromosomal karyotypes were examined.Results:The successful rate of amniotic fluid cells culture was 95.8%(126/132).Ten chromosomal abnormalities(7.8%)were checked out.Trisomy,the leading abnormality,consisted of 40%(4/10)of all abnormalities and 3 out of 4 were trisomy 21,(first present a case of trisomy 21 in both two fetused of monozygotic twins).Sex chromosome aneuploidey was found in 1 fetus.Balanced translocation was found in 1 fetus associated with Robertsonian translocation.IVV9 was found in 4 fetuses.No abortion was caused by the amniocentesis.Conclusion:During the second trimesters,the rate of chromosomal abnormality is 7.8%in those fetuses who have maternal indications for prenatal diagnosis.Trisomy,especially trisomy 21,is the most common abnormal karyotype foud in these periods and in advanced maternal age.The amniocentesis with B-ultrasound screened and located also play important role in prenatal diagnosis.