染色体三体胎儿妊娠期临床表现—20例产前诊断分析

通过妊娠中、晚期脐带穿刺取胎血做染色体核型分析，检出的各种三体胎儿20例，分析其产前诊断指征、母亲年龄、临床表现、B超检查结果。结果显示：21、18、13三体占三体胎儿的90．0％。21三体为胎儿最常见的三体。高龄母亲占45．0％（9／20）。所有三体儿在妊娠中期均无表现。在妊娠晚期，胎儿宫内发育迟缓（intrauterine growth retardation,IUGR)为最常见的临床表现：而B 提示羊水过多及胎儿畸形为18三体的特征性表现。与18三体比较，21三体儿B超下相对缺乏表现。因此，为提高三体儿的检出率，对内因性匀称型IUGR，应取羊水或脐血做产前诊断，18三体儿多可通过孕晚期B超检查发现异常；而21三体儿的诊断则需结合母亲血清学筛查指标，最后通过羊水或脐血染色体核型检查方可确诊。

The clinical features of trisomic fetuses during gestation - an analysis for 20 cases of prenatal diagnosis

By codocentesis and them chromosomal analysis.20 trisomic fetuses were found during the second and third trimesters.It was investigated that the indications for prenatal diagnosis,maternal ages,clinical symptoms,and the results of ultrasonic examination.It was showed that the major types of eftal trisomy were trisomy 21,18,13,which consisted of 90.0%.Trisomy 21,according to our data,was the most common trisomic karyotype in fetuses.There were 45% mothers with advanced age (9/20).All trisomic fetuses did not have any clinical features during the second trimester.In the third trimestes,however,Intrauterine growth retardation(IUGR) was the most common symptom.By ultrasonic examination,polyhydramnias associated with malformations was characteristics for trisomy 18. Nevertheless,Comparing with trisomy 18,trisomy 21 had less phenomena.For finding out more trisomy before birth,prenatal diagnosis should be done for the fetuses with symmetric IUGR.In the third trimester trisomy 18 can be quite easily found by ultrasound because of its features.In order to diagnose those fetuses with trisomy 21,it is necessary to combine with other indications of maternal serum screening.Finally,to confirm the diagnosis either amniocentesis or cordocentesis should be employed for cheking chromosomal karyotype.