[Cytogenetic studies of spontaneous abortions in humans].

Karyotypes were analyzed using directing method for chorionic villi chromosome preparation in 52 specimens from spontaneous abortions. A paralleled cytogenetic study of 51 specimens from induced abortions was carried out. Among 52 specimens from spontaneous abortions, 11 (21%) were chromosomally abnormal and 82% of these were found to have autosomal trisomies (3,14,16,19,20 and 21). Trisomy 16 was the most common abnormality accounting for 44% of trisomic abortuses. A double trisomic abortus with a 48, XX, +16, +20 karyotype was detected. These results showed that chromosome abnormality is an important cause of spontaneous abortion. The relationship between chromosomal abnormalities of spontaneous abortuses and the factors relevant to the abnormalities are discussed.