Does High Risk for Down Syndrome Screening Mean There’s a Chromosome Abnormality in the Fetus?

Question

I’m a woman who has undergone a Down syndrome screening during pregnancy. The report shows high risk. Does this mean the fetus might have a chromosomal abnormality?

Answer

It is recommended to undergo non-invasive prenatal testing (NIPT) or amniocentesis to confirm. NIPT has a high accuracy rate of up to 99%, but it only tests for three pairs of chromosomes (trisomy 13, 18, and 21). To test all 23 pairs of chromosomes comprehensively, amniocentesis is required, which can reach a 100% accuracy rate and is the gold standard for diagnosis. However, amniocentesis carries a small risk of miscarriage, although the risk is lower than 3%. If you are concerned about the risk of amniocentesis, you can opt for NIPT. But if the NIPT result still shows an abnormality, further amniocentesis is necessary.