妊娠中晚期羊水细胞胎儿染色体异常核型分析

目的:分析妊娠中、晚期胎儿羊水染色体核型,了解该时期异常核型出现的频率类型及与诊断指征的关系。方法:357例有产前诊断指征的孕妇,在妊娠13-17行羊膜腔穿刺术,取羊水细胞培养,分析胎儿染色体核型。结果:羊水细胞培养成功率91.6%,发现异常核型21例(6.4%),其中妊娠中期检出异常5.7%(16/282);晚期异常11.1%(5/45),P>0.05。染色体异常携带者和各种三体为主要的异常核型,分别占52.4%(11/21)和33.3%(7/21)。高龄孕妇异常检出率为10.2%(5/49),非高龄组为5.8%(16/278),P>0.05。平衡易位组为52.4%,(11/21);胎儿宫内发育迟缓(IUGR)16.7%(1/6)血清学筛查风险值增高为5.9%(1/17)。结论:在有产前诊断为指征的孕妇,胎儿染色体异率为6.4%,染色体异常携带者和各种三体为主要的异常,是高龄以及IUGR最常见的异常。羊水细胞培养对于中、晚期妊娠的高风险孕妇行产前诊断是安全、可靠、诊断方法之一。

Analysis of abnormal chromosomal karyotypes in fetal amniotic fluid cells during the second and third trimesters of gestation

Objective:To analyze the fetal chromosomal karyotypes (Chr-kar) from the amniotic fluid cells(AFC)cultured during the second and third trimesters;To investigate types of chromosomal abnormalities (Chr-abn) and the relationship between the abnormal karyotypes and the indications for prenatal diagnosis.Methods:Amniocenteses were performed in 357 pregnancy with different indications for prenatal diagnosis during the 13 to 37 gestational weeks to culture AFC and exam the fetal Chr-kar.Results:Successful rate for diagnosis was 91.6%,and 21 Chr-abn were checked out.Carriers of Chr-abn were 52.4%and trisomies were 33.3%.In those advanced ages,Chr-abn were detected in 10.2%,and in the young was 5.8%,P>0.05.Balanced translocation was found in 11 fetuses.There was one Chr-abn in six fetuses with IUGR.Trisomy 21 was detected in 1 of 17 fetuses with high risk rate by maternal serum prenatal screening.Conclusion:During the second and third trimesters,the rate of Chr-abn was 6.4%.Balanced translocation and trisomy were the most common abnormal karyotypes found in these periods and in advanced maternal age,as well as severe IUGR.