[Cytogenetic study of 1780 cases of spontaneous abortion].

OBJECTIVE

To explore the relationship between chromosome anomaly and spontaneous abortion, and to provide useful information for genetic counseling and prenatal diagnosis in reproductive clinic.

METHODS

A total of 1 780 patients who had a history of spontaneous abortion before 24 weeks of gestation were enrolled. The lymphocyte culture and harvest were performed according to standard methods. Karyotypes were analyzed by G-banding in all cases and C- banding in some cases in addition.

RESULTS

Altogether 57 abnormal karyotypes were found and the overall incidence of chromosomal abnormalities was 3.20% (women 3.32%; men 2.12%). Among them 23 cases were the balanced translocation; 14 cases were the Robertsonian translocation, 3 cases were the complex chromosomal rearrangement, and the other 17 cases were the other abnormalities. In women with 1, 2, 3 or more spontaneous abortion, the incidence of chromosomal abnormalities was 1.7%, 2.3%, and 5.8%, respectively.

CONCLUSION

Translocations are the major abnormal karyotpes associated with spontaneous abortions. The chance of finding chromosomal aberration increases with the number of abortions. Chromosomal abnormalities are more common in women with 3 or more spontaneous abortions.