[Trisomy 22--prenatal findings in various developmental stages]

Four cases of trisomy 22 in different stages of pregnancy are reported, one of them showing a mosaicism. The diagnosis was made in three of the observations during the first trimenon, in one in the third trimenon. A typical pattern of malformations of developmental retardation could be demonstrated in the embryonic as well as in the extraembryonic tissues. Our findings confirm the different frequency of the single chromosome abnormality in the various stages of development in pregnancy.