Abstract: Objective：To estimate the frequency of chromosomal abnormalities, and to explore the relationship between chromosomal abnormalities and sex，abortion times，gestational age and abnormal childbearing history. Methods：The chromosome karyotyping and clinical characteristics were retrospectively analyzed in 1 770 couples with spontaneous abortion. Results：Chromosomal abnormalities and polymorphisms were detected in 111 cases （３．１４％） and 119 cases （３．３６％）, respectively. 41 cases （２．３２％） of chromosomal abnormalities were found in male while 70 cases （３．９５％） in female. The abnormal childbearing rate in those chromosome-abnormal couples was 6.36%, while the normal childbearing rate in those couples was 1.8%, respectively. There was no significant difference in early miscarriage rates between those abnormality couples and controls（P＞0.05）. The rate of spontaneous abortion in those couples with chromosomal translocation （５５．１％） was higher than that in normal couples （２５．０％，P＜0.001）, while this rate in those couples with chromosomal inversion did not significantly change（P＞0.05）. There was significant difference in the rate of multiple spontaneous abortion in those heterochromatin/satellite heteromorphism carriers （３７．３％） when compared with normal couples as well as chromosome-translocation couples（P=0.007，P=0.036）. Conclusions：In those couples with spontaneous abortion, the rate of chromosomal abnormalities was more frequent in female than that in male. Chromosomal abnormalities were closely related to abortion times, abnormal childbearing history, suggesting that chromosomal abnormalities are risk factors of spontaneous abortion.

Key words: Abortion, spontaneous, Cytogenetics, Chromosome aberrations, Polymorphism, genetic, Karyotyping