NIPT (cell-free DNA prenatal screening)

cfDNA screening for the common trisomies (21/18/13); a screening test that requires confirmation.

Screening risk for trisomy 21/18/13 (± sex chromosomes and fetal sex); confirmation advised if high-risk.

Evidence: Well-established; prenatal exome maturing

cfDNA/NIPT is a highly accurate screening test for the common trisomies. Microarray and QF-PCR are first-line diagnostics on invasive samples, with prenatal exome adding yield in selected cases.

Limitations

cfDNA/NIPT is a screening test, not a diagnosis: a high-risk result requires confirmatory invasive testing, and performance for microdeletions is more limited than for the common trisomies.

Prenatal: published evidence

This test needs genetic counselling and written consent; your clinic confirms both at ordering.

• Fetal Karyotype

  Full chromosome analysis of the baby.

• Array-CGH (microarray)

  Detects missing or extra chromosome pieces.

• QF-PCR

  Rapid check for the most common chromosome conditions.

• Whole-Exome Sequencing

  Deep gene sequencing to find a suspected genetic cause.