For what purpose is FISH NOT recommended during pregnancy management?

Fluorescence in situ hybridization (FISH) is a powerful technique used in genetic testing, particularly for the identification of chromosomal abnormalities. However, its utility in pregnancy management can be limited for certain reasons.

The reason FISH is not recommended primarily relates to its inability to provide comprehensive analysis in specific contexts, particularly for discerning microdeletions and duplications. While FISH can rapidly identify certain aneuploidies, it is not designed to detect all genetic alterations, especially smaller chromosomal changes like microdeletions. Other methods, such as microarray comparative genomic hybridization (aCGH), are more appropriate for this type of analysis during pregnancy.

Although FISH may provide preliminary results quite quickly for detecting specific chromosomal changes, it lacks the breadth of detection capabilities required during pregnancy management for more nuanced genetic assessments. Hence, when considering the value of genetic testing during pregnancy, the inability of FISH to detect a wide range of microdeletions is a significant limitation.

In contrast, the issues of speed and cost associated with FISH can vary depending on the laboratory and the specifics of the case, and while these factors are noteworthy in the context of genetic testing, they do not directly pertain to the limitations