The genetic testing prevents Chromosomal diseases. They have an adverse impact on individuals and families. Parental testing helps to gain the knowledge about the possibility of the abnormalities in the unborn according to the chromosomal disorder which can also get carried to their offspring.
Chromosomal disorder causes almost half of the abortions occurring before the first trimester during pregnancy. This condition is called concepts, it is desirable to screen chromosomal disease to clarify the health of the unborn and the mother during the parental tests.
Other types of chromosomal disorder are;
Translocations – reciprocal exchange between two chromosomes which are non homologous. The genetic material gets exchanged with the arm break procedure. An unbalanced translocation leads to no loss and no gain of genetic material.      
          
Inversions - the segment between the chromosomes invert before they are repaired automatically when chromosome breaks into two is called inversions. This leads to gene sequence alteration.
Maternal meiotic non disjunction is a condition met by mothers with late reproductive age. These

results in a chromosomal disease called autosomal trisomies. Maternal meiosis leads to another chromosomal disease called Trisomy. The advanced age the fetal enhances aneuploidy. The situation of meiotic errors may occur. Thus karyotype     analysis should also be done along with testing for chromosomal disorders during parental testing.