Why routine biochemical tests are important?

Question

NIPT genetic test has sensitivity of more than 99.9% but is a screening test. It is necessary to confirm the high risk results from the test by additional Invasive Prenatal diagnostic tests such as FISH/ Karyotype or Microarray. Non-Invasive Prenatal Testing is a blood test taken from the mother during pregnancy that uses DNA technology to evaluate accurately whether a baby has a high chance of a certain chromosomal condition.