Limitations
A small percentage (1-2%) of pregnancies have confined placental mosaicism, where some but not all of the placental cells tested in the CVS are abnormal, even though the pregnancy is unaffected. Cells from the mother can be mixed with the placental cells obtained from the CVS procedure. Occasionally if these maternal cells are not completely separated from the placental sample, this can lead to discrepancies with the results. This phenomenon is called Maternal Cell Contamination (MCC). CVS cannot detect all birth defects. It is used for testing chromosomal abnormalities or other specific genetic disorders only if there is family history or other reason to test.
Read more about this topic: Chorionic Villus Sampling
Famous quotes containing the word limitations:
“The limitations of pleasure cannot be overcome by more pleasure.”
—Mason Cooley (b. 1927)
“That all may be so, but when I begin to exercise that power I am not conscious of the power, but only of the limitations imposed on me.”
—William Howard Taft (1857–1930)
“Growing up means letting go of the dearest megalomaniacal dreams of our childhood. Growing up means knowing they can’t be fulfilled. Growing up means gaining the wisdom and skills to get what we want within the limitations imposed by reality—a reality which consists of diminished powers, restricted freedoms and, with the people we love, imperfect connections.”
—Judith Viorst (20th century)