Analysis the result of 74330 amniocentesis

Among 74330 amniocentesis tests that have been performed during 18 yearsin this center. There are 2532 (0/3.4%) cases of chromosomal abnormalitycomprising 2015 (0/2.7%) autosomal and 517 (0/0.7%) of sex chromosomalabnormality. Chromosome 21 making 1401 cases is the most causes ofchromosomal abnormality, fallowed 237 cases of trisomy chromosome 18,Hundred fourteen cases of partial trisomy, 106 cases of monosomy 21.Seventy eight cases of trisomy 13, fifty eight cases of chromosomalmonosomy, 11 cases of trisomy 9, finally 10 cases of choromosomalabnormalities, which are presented in table A, there are also 318 cases of sexchoromosomal abnormality is presented in table B. Trisomy of chromosome21(down syndrome) and monosomy of chromosome X (Turner Syndrome) arethe most abnormality of autosome and sex chromosome aberration.