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

What factor is key when looking for chromosome abnormalities in cases of fetal loss?

1. Microscopic examination of maternal blood

2. Analysis of chorionic villi

3. Use of whole blood culture

4. Immunostaining of the parental kinotypes

The correct answer is: Analysis of chorionic villi

The analysis of chorionic villi is a key factor when looking for chromosome abnormalities in cases of fetal loss because chorionic villus sampling (CVS) provides a direct and early means of obtaining fetal tissue for genetic analysis. The chorionic villi, which are the projections from the placenta, contain cells that are genetically identical to the fetus. This allows for the detection of chromosomal abnormalities such as aneuploidies, deletions, or duplications at an earlier stage than other methods. In cases of fetal loss, especially when there is a need to quickly understand if there were any chromosomal abnormalities that may have contributed to the loss, utilizing chorionic villi is particularly advantageous. The rapid generation of results from this source can guide decisions in future pregnancies and help with genetic counseling. Other methods, such as microscopic examination of maternal blood or whole blood culture, do not provide direct access to fetal tissue, making them less effective for this specific purpose. Immunostaining of parental kinotypes generally focuses on analyzing cellular components and is not a standard approach for directly checking for chromosomal abnormalities in the context of fetal loss.