Chromosome abnormalities in newborn children. Physical aspects.

A chromosome examination was made on 11,148 consecutively live-born children: 93 had a chromosome abnormality and 192 a chromosome variant. The physical aspects of the children with chromosome abnormalities and variants were compared with those of the children with normal karyotypes. Children with aneuploid or unbalanced chromosome abnormalities were more immature or not fully developed at birth than those with normal karyotypes. Birth weight was lower in children with all types of chromosome abnormalities, including reciprocal translocations and chromosome variants. The low birth weight in children with chromosome variants was mainly due to the low birth weight of children with G variants. These children were also subject to a higher frequency of special delivery treatment. Heart disorders were increased in children with aneuploid or unbalanced chromosome abnormalities. The frequency of foetal erythroblastosis was increased in children with short Y as well as in children with acentric fragments. Neonatal mortality was higher in children with aneuploid or unbalanced chromosome abnormalities than in children with normal karyotypes.