Non-Invasive Prenatal Genetic Screening for Fetal Chromosomal Aneuploidies (NIPS), Whole Blood

Diagnostic Use

NIPS is a highly sensitive and specific screening test for Trisomy 21 (Down Syndrome), Trisomy 18 (Edward Syndrome) and Trisomy 13 (Patau Syndrome) performed on a sample of maternal blood. The test can be performed from the 10th week of gestation.

Testing can be performed in singleton and twin pregnancies.

Requests for NIPS are only accepted on a fully completed CHL request form available from the laboratory.

NIPS is a screening test with a sensitivity of >99% for Trisomy 21, Trisomy 18 and >85% for Trisomy 13. A ‘low risk’ result does not completely exclude foetal chromosomal abnormality. A ‘high risk’ result should be followed up by specialist referral for diagnostic testing.

In about 3% of tests, it is not possible to provide a result due to a low concentration of foetal DNA relative to maternal DNA (low foetal fraction) and a ‘No result’ will be issued. The foetal fraction decreases with increasing maternal weight, such that the risk of a ‘No result’ is about 20% in a woman with a maternal weight of 95 kg.

Department

Maternal Screening

Delphic Registration Code

NIPS

Laboratory Handling

Phlebotomy

STRECK BCT tube must have more than 7 mL of blood (otherwise sample is rejected), please check the request form and consent form are signed.

Registration

Please scan consent form and request form.

Separating

Keep sample at room temperature, the tubes should not be separated or frozen, send to MSS lab. (80122)

Laboratory

Sample is stable at room temperature until sent to VCGS.

Synonyms

NIPT

Turnaround Time

14 days