Which procedure is recommended as the primary test for prenatal diagnosis of fetal structural abnormalities?

Microarray testing is recognized as the primary test for the prenatal diagnosis of fetal structural abnormalities because it offers a more comprehensive analysis of potential chromosomal abnormalities compared to traditional karyotype analysis. Specifically, microarray can detect copy number variations (CNVs) in the genome that may not be visible with standard karyotype analysis, which typically looks for larger chromosome abnormalities.

This advanced technique provides higher resolution for identifying submicroscopic deletions and duplications, making it particularly effective for diagnosing conditions such as congenital anomalies associated with genetic disorders. As a result, microarray testing has become the preferred method due to its ability to provide detailed insights into fetal genomic integrity and associated structural abnormalities in a single test.

While karyotype analysis, amniocentesis, and serum screening all provide valuable information, they do not have the same level of sensitivity and specificity in identifying subtle genomic changes as microarray testing does. Karyotyping is limited to detecting larger chromosomal anomalies, amniocentesis is an invasive procedure that carries risks, and serum screening primarily assesses risk rather than directly diagnosing structural abnormalities. Therefore, microarray testing stands out as the most effective initial diagnostic tool in prenatal care for identifying fetal structural abnormalities.