研究新生儿脐带血中染色体异常的发生率，并对脐带血染色体数目与结构异常及染色体多态性进行综合分析。

对新生儿脐带血进行收集，进行淋巴细胞培养，常规G显带，行染色体核型分析。

在培养成功的15 500例脐带血标本中，检出异常核型314例，在人群中的发生率为2.03%；其中染色体倒位患儿220例，发生率1.42%，构成比70.10%；染体易位患儿41例，发生率0.26%，构成比13.00%；染色体衍生患儿14例，发生率0.09%，构成比4.51%；21-三体患儿12例，发生率0.08%，构成比3.80%；D-G组易位患儿11例，发生率0.08%，构成比3.50%；性染色体异常中47，XXX患儿5例，47，XXY患儿7例，45，X患儿4例，发生率0.10%，构成比5.10%。染色体多态性检出317例，其发生率为2.04%。其他各组与倒位组发生率及构成比比较，均差异有统计学意义(χ²＝11.53，15.98；P<0.05)；而易位、衍生、21-三体、D-G组易位及性染色体异常等发生率比较，差异无统计学意义(P>0.05)，各组异常自然发生率比较接近。

新生儿脐带血染色体核型分析，对目前产前诊断不足具有很好的补充意义，对二级预防、再生育及临床指导有重要意义。

To study the incidence of chromosomal abnormalities in the umbilical cord blood, and analyze the number and structure and chromosome poly-morphism of the cord blood.

Umbilical cord blood was collected for lymphocyte culture, conventional G-banding and karyotype analysis.

15 500 cases of umbilical cord blood samples were detected, of which 314 cases were abnormal karyotypes, the rate was 2.03%.Chromosomal inversions of children were 220, the percentage in population was 1.42%, the constituent ratio was 70.10%.Chromosomal translocations samples were 41, the percentage in population was 0.26%, the constituent ratio was 13.00%.Chromosome-derived samples were 14, the percentage in population was 0.09%, the constituent ratio was 4.51%.Children with 21-Down Syndrome samples were 12, the percentage in population was 0.08%, the constituent ratio was 3.80%.Children with displaced robertson were 11, the percentage in population was 0.08%, the constituent ratio was 3.50%.In sex chromosome abnormalities, 47, XXX were 5, 47, XXY were 7, 45, X were 4, the percentage in population was 0.10%, the constituent ratio was 5.10%.Children with chromosomal polymorphism were 317, the percentage in population was 2.04%.Compared with the other groups, the chromosomal inversions group′ proportion and constituent ratio were significantly different (χ²=11.53, 15.98; P<0.05). The differences among translocateon, chromosome-derived, 21-Down Syndrome, D-G group and sex chromosome abnormal incidence were not significant (P>0.05), the incidence of abnormal natural of each group was closer.

Karyotype analysis of neonatal umbilical cord blood is a very useful to the insufficient prenatal diagnosis, and important for secondary prevention, fertility and clinical guidlines.