DNA sequencing versus standard prenatal aneuploidy screening

Area of Science:

• Genetics
• Obstetrics
• Molecular Biology

Background:

• Noninvasive prenatal testing using cell-free DNA (cfDNA) accurately detects fetal aneuploidy in high-risk pregnancies.
• The performance of cfDNA testing in low-risk populations remained unclear prior to this study.

Purpose of the Study:

• To compare the false positive rates of cfDNA testing versus standard aneuploidy screening methods.
• To evaluate the diagnostic performance of cfDNA testing in a general obstetrical population.

Main Methods:

• Massively parallel sequencing of maternal plasma cfDNA was performed in a blinded manner.
• Standard aneuploidy screening involved serum biochemical assays and/or nuchal translucency measurements.
• Birth outcomes and karyotypes served as the reference standard for comparison.

Main Results:

• cfDNA testing demonstrated significantly lower false positive rates for trisomies 21 and 18 (0.3% vs. 3.6% and 0.2% vs. 0.6%, respectively).
• The negative predictive value for cfDNA testing was 100%, detecting all aneuploidy cases (trisomies 21, 18, and 13).
• Positive predictive values for cfDNA testing were substantially higher than standard screening for trisomy 21 (45.5% vs. 4.2%) and trisomy 18 (40.0% vs. 8.3%).

Conclusions:

• In the general obstetrical population, cfDNA testing offers superior performance over standard screening for trisomies 21 and 18.
• The study highlights the clinical utility of cfDNA testing due to its lower false positive rates and higher positive predictive values.