Antenatal screening for fetal trisomies using microarray‐based cell‐free DNA testing – a systematic review and meta‐analysis

Objective To evaluate the test accuracy of non‐invasive prenatal testing (NIPT) for fetal trisomy 21, 18, and 13 using cell‐free (cf) DNA analysis in maternal plasma with microarray quantitation. Method Systematic review and meta‐analysis. Searches in MEDLINE, Pre‐MEDLINE, EMBASE, Web of Science, and the Cochrane Library to 09.07.2018. Results Five studies analyzing 3074 samples, including 187 trisomy 21, 43 trisomy 18, and 19 trisomy 13 cases, were identified. Risk of bias was high in all studies, introduced particularly by exclusions from analysis and by the role of the sponsor. Sensitivity of microarray‐based cfDNA testing was 99.5% (95%CI 96.3%‐99.9%) for trisomy 21, 97.7% (95%CI 87.9%‐99.6%) for trisomy 18, and 100% (95%CI 83.2%‐100%) for trisomy 13. Specificity was 100% (95% CI 99.87%‐100%) for trisomy 21, 99.97% (95%CI 99.81%‐99.99%) for trisomy 18, and 99.97% (95%CI 99.81%‐99.99%) for trisomy 13. Pooled test failure rate was 1.1%. A direct comparison of microarray‐ and sequencing‐based cfDNA found equivalent test accuracy. Conclusion Included studies suggest that NIPT using microarray‐based cfDNA testing has high sensitivity and specificity for detecting fetal trisomy 21, 18, and 13. However, the evidence base is small and at high risk of bias.