Non-Invasive Prenatal Testing (NIPT): 99% Accurate Early Genetic Screening

Cell-free fetal DNA screening from maternal blood at 9+ weeks safely detects Down, Edwards, and Patau syndromes.

1. Molecular Principles of NIPT

Non-Invasive Prenatal Testing (NIPT) isolates and sequences cell-free fetal DNA (cffDNA) originating from trophoblast placental apoptosis circulating in maternal venous blood. It can be safely performed as early as gestational week 9 to 10 from a simple 10ml peripheral maternal blood sample.

2. Clinical Screening Scope

Common Autosomal Aneuploidies: Trisomy 21 (Down syndrome - sensitivity >99.7%), Trisomy 18 (Edwards syndrome - sensitivity 98%), and Trisomy 13 (Patau syndrome - sensitivity 99%).
Sex Chromosome Aneuploidies: Turner syndrome (45,X), Klinefelter syndrome (47,XXY), Triple X (47,XXX), and Jacobs syndrome (47,XYY).
Pathogenic Microdeletions: Submicroscopic chromosomal copy number variants such as 22q11.2 deletion (DiGeorge), 1p36 deletion, and Angelman syndrome.

3. Superiority Over Conventional Serum Screening

NIPT delivers an exceptionally low false-positive rate (<0.1%) compared to conventional first-trimester biochemical screens (Double Test) which harbor a 5% false-positive rate. This dramatic specificity eliminates up to 95% of unnecessary invasive diagnostic amniocenteses, sparing families procedural miscarriage risks.