The shortage of chromosome 12 by amniocentesis suggests that there is a deletion of autosomal chromosome 12. The embryo in this pregnancy may not develop into a normal fetus and the pregnancy needs to be terminated. This is because a normal human body has 23 pairs of chromosomes, the first 22 pairs are autosomes and the last pair is the sex chromosome, which will be used to determine the sex of the fetus. During pregnancy, amniocentesis can be performed to check for chromosomal abnormalities and to rule out chromosomal disorders in the fetus. chromosome 12 belongs to one of the autosomes, and the deletion of chromosome 12 is a chromosomal abnormality, which may be related to the genetic factors of both spouses, or it may be due to chromosomal mutations, so that the child may have growth and development and intellectual abnormalities. In addition, with a chromosome 12 deletion, spontaneous abortion may also occur early in pregnancy. Because it is a chromosomal disorder, there is no effective treatment for chromosome 12 deletion. Therefore, once a chromosome 12 deletion is diagnosed during pregnancy, regardless of the number of weeks of pregnancy, an abortion or induction of labor should be performed.