The Use of Chromosomal Microarray Analysis in Prenatal Diagnosis

Area of Science:

• Genetics
• Prenatal Diagnosis
• Cytogenomics

Background:

• Karyotype analysis has limitations in detecting smaller chromosomal abnormalities.
• Copy number variants (CNVs) are associated with significant clinical implications in pregnancies.
• Chromosomal microarray analysis (CMA) offers higher resolution for detecting microdeletions and duplications.

Purpose of the Study:

• To highlight the diagnostic utility of CMA in prenatal settings.
• To emphasize the importance of CMA as the current standard for cytogenomic analysis.
• To inform clinicians about CMA technologies and reporting.

Main Methods:

• Review of CMA technology and its application in prenatal diagnosis.
• Analysis of CNV detection rates in pregnancies with and without ultrasound anomalies.
• Discussion of clinical significance and genetic counseling requirements.

Main Results:

• CMA identifies microdeletions and duplications missed by karyotyping.
• CNVs occur in 1% to 1.7% of pregnancies, with higher detection rates (approx. 6%) in those with ultrasound anomalies.
• CMA is the current standard for cytogenomic analysis in specific obstetric indications.

Conclusions:

• CMA should be offered to all women undergoing invasive prenatal testing.
• Clinicians require familiarity with CMA technologies and reporting.
• Comprehensive pretest and posttest genetic counseling are essential for abnormal CMA findings.