What is NIPT, and can it diagnose Down syndrome?
Non-invasive prenatal testing examines cell-free DNA in maternal blood to estimate the chance of certain chromosome-number conditions, including Down syndrome. It is usually available from ten weeks, but is screening rather than diagnosis. A higher-chance result needs counselling and discussion of confirmatory diagnostic testing.
Details
Why is “high accuracy” not enough?
Much of the pregnancy-related DNA being assessed comes from the placenta. The meaning of a result depends on the condition and its prior likelihood, and false-positive or false-negative results can occur. A higher-chance result is not proof that the fetus is affected.
What follows the result?
The team may discuss amniocentesis or chorionic villus sampling for confirmation. An uninterpretable result is not a low-chance result and needs an individual follow-up plan. Do not base an irreversible pregnancy decision on screening alone.
What is not covered?
NIPT does not detect every inherited or structural condition and does not replace ultrasound. Before testing, ask which conditions are included, what limitations apply and how results would guide care.
Related reading: When is amniocentesis considered, and what are its benefits and risks?.