Non-Invasive Prenatal Testing (NIPT) analyzes small fragments of fetal DNA circulating in the mother’s blood to screen for common chromosomal conditions (such as Down syndrome) starting from around the 10th week of pregnancy. It’s a screening test, not diagnostic – meaning a high-risk result would typically be followed up with a diagnostic test like amniocentesis or CVS (chorionic villus sampling), which directly samples fetal tissue for confirmation.