Screening for 23 pairs of chromosomes screens for numerical and structural abnormalities in the 23 pairs of chromosomes. If there are numerical abnormalities and structural abnormalities, the disease that manifests is more serious or even fatal, such as numerical abnormalities. However, if there is more than one chromosome, such as trisomy 21 or trisomy 18, and the genetic traits exhibited are more serious when they turn from diploid to triploid, most of the children born are congenitally stupid and stop developing and abort naturally when they are found earlier.