American Society for Clinical Pathology (ASCP) Technologist in Cytogenetics certification (ASCP CG) Practice Test

What type of cell is primarily analyzed with the CVS direct preparation?

1. Cytotrophoblast

2. Amniocyte

3. Fibroblast

4. Blastocyst

The correct answer is: Cytotrophoblast

The cytotrophoblast is the correct answer because it is the type of cell primarily analyzed in chorionic villus sampling (CVS) direct preparations. CVS is a prenatal test performed to obtain a sample of chorionic villi, which are finger-like projections derived from the placental tissue. These villi contain cytotrophoblast cells, which are critical for evaluating the genetic material of the fetus. Cytotrophoblasts play a significant role as they contribute to the formation of the placenta and have direct genetic implications for fetal development. By analyzing the cytotrophoblast cells, clinicians can assess chromosomal abnormalities and genetic disorders early in pregnancy, often as early as the first trimester. In contrast, amniocytes are the primary cell type analyzed in amniocentesis and are not relevant for CVS, as this procedure is focused on collecting chorionic villi. Fibroblasts are typically derived from skin or connective tissue, rather than from the placenta or fetal tissues. The blastocyst refers to an early stage of embryonic development that precedes implantation, making it irrelevant to CVS direct preparations. Thus, the cytotrophoblast is specifically the target cell in CVS due to its direct relationship with placental genetics and fetal health