1075例产前诊断胎儿染色体核型分析

目的:探讨因不同指征行产前诊断的孕妇中胎儿染色体异常的类型及出现频率。方法:回顾性分析2004年10月~2009年8月在广西壮族自治区人民医院因各种原因行羊膜腔穿刺或脐带血穿刺产前诊断的胎儿染色体核型。结果:1 075例产前诊断中发现胎儿染色体异常32例,染色体异常检出率2.97%。其中因唐氏综合征高危行产前诊断者中胎儿染色体异常检出率1.82%;因高龄行产前诊断者中胎儿染色体异常检出率1.82%;因18、13-三体筛查高危行产前诊断者染色体异常检出率1.35%;因畸胎史行产前诊断者中胎儿染色体异常检出率2.70%;因孕早期用胚胎毒性药物行产前诊断者中胎儿染色体异常检出率2.77%;因有自然流产史或本次妊娠有先兆流产而行产前诊断者中胎儿染色体异常检出率均为0;因孕11~14周B超检查示NT值大于2.5 mm行产前诊断者中胎儿染色体异常检出率5.41%;因B超检查示羊水少、胎儿单脐动脉、心室强光斑、胎儿肾盂分离行产前诊断者胎儿染色体异常检出率7.14%;因生育过唐氏综合征患儿行产前诊断者胎儿染色体异常检出率25.00%;因夫妻双方之一为染色体平衡易位行产前诊断者中胎儿染色体异常检出率88.89%;因有生育重型地中海贫血患儿风险行产前诊断者胎儿染色体异常检出率1.35%。结论:除夫妻双方之一为染色体平衡易位及生育过唐氏综合征患儿者外,B超检查示羊水少、胎儿单脐动脉、心室强光斑、胎儿肾盂分离的胎儿中染色体异常检出率高,其次为NT值大于2.5 mm的胎儿,再次为孕早期用胚胎毒性药物、因畸胎史行产前诊断者、孕妇高龄及唐氏综合征高危。孕中期胎儿系统的B超检查,孕11~14周B超测NT值及孕中期血清学唐氏综合征筛查可以从人群中筛查出染色体异常高危胎儿,提高产前诊断的效率,减少出生缺陷儿。

Analysis on 1075 cases of fetal chromosome karyotypes in prenatal diagnosis

Objective:To study the types and occurrence frequency of the fetal chromosome abnormality among pregnant women who have received a prenatal diagnosis due to the different indications.Methods:To analyze the fetal chromosome karyotypes which were performed the amniocentesis or cordocentesis in prenatal diagnosis due to various reasons in our hospital from October 2004 to August 2009.Results:In 1 075 cases,the number of fetal chromosome abnormality was 32 in prenatal diagnosis,and the detection rate of chromosome abnormality was 2.97%.Among them,the detection rate of fetal chromosome abnormality of patients who had received the prenatal diagnosis due to the high risk for Down syndrome was 1.82%;the detection rate of fetal chromosome abnormality of patients who had received the prenatal diagnosis due to the advanced maternal age was 1.82%;the detection rate of fetal chromosome abnormality of patients who had received the prenatal diagnosis due to the high risk for trisomy 18 and trisomy 13 was 1.35%;the detection rate of fetal chromosome abnormality of patients who had received the prenatal diagnosis due to the history of teratism was 2.70%;the detection rate of fetal chromosome abnormality of patients who had received the prenatal diagnosis due to the use of embryotoxicity medicine in early pregnancy was 2.77%;the detection rate of fetal chromosome abnormality of patients who had received the prenatal diagnosis due to the history of spontaneous abortion or the threatened abortion of gestation was 0;the detection rate of fetal chromosome abnormality of patients who had received the prenatal diagnosis due to the NT value shown by the ultrasonic B examination at 11～14 weeks of gestation was higher than 2.5mm was 5.41%;the detection rate of fetal chromosome abnormality of patients who had received the prenatal diagnosis due to the following reasons was 7.14%: oligohydramnios,single umbilical artery,strong facula in ventricle,fetal pyelic separation;the detection rate of fetal chromosome abnormality of patients who had received the prenatal diagnosis due to the fact that they once gave birth to a baby with Down syndrome was 25%;the detection rate of fetal chromosome abnormality of patients who had received the prenatal diagnosis due to the chromosome balanced translocation of one of the couple was 88.89%;the detection rate of fetal chromosome abnormality of patients who had received the prenatal diagnosis due to the risk of giving birth to a baby with heavy thalassemia was 1.35%.Conclusion:Except the patients who have the problem of chromosome balanced translocation and once gave birth to a baby with Down syndrome,the highest detection rate of fetal chromosome abnormality can be seen in those fetuses with oligohydramnios,single umbilical artery,strong facula in ventricle and fetal pyelic separation.The second highest are those fetuses with NT value above 2.5mm.The third highest are those who have taken embryotoxicity medicine in early pregnancy and who have received the prenatal diagnosis due to the history of teratism,elderly pregnant women and those at high risk for Down syndrome.The high risk fetuses with chromosome abnormality can be examined by the following methods,so as to improve the efficiency of prenatal diagnosis and reduce the birth defects: adopting the ultrasonic B examination at midgestation,measuring the NT value with the ultrasonic B examination at 11~14 weeks of gestation and adopting the serologic screening for Down syndrome at midgestation.