Spontaneous abortion. Chromosome studies on 41 cases and an analysis of maternal age and duration of pregnancy in relation to karyotype.

Abstract The relatively frequent occurrence of chromosomal abnormalities in spontaneous abortuses offers an opportunity to gain additional insight into the mechanisms and consequences of alterations in the karyotype. Studies on 41 successfully cultured specimens showed abnormalities belonging to each of the three major classes previously reported (autosomal trisomy, X-monosomy, and triploidy) as well as one case of mosaicism and one with a structural abnormality. Analyses of pooled data showed a higher mean maternal age and shorter mean period of gestation for trisomic abortuses than for abortuses associated with X-monosomy, triploidy, and normal chromosomes. No influence of maternal age could be demonstrated for X-monosomic or triploid abortions when these were compared with abortions having normal chromosomes. An association of triploidy with missed abortion was noted and may be significant.