Non-Invasive Prenatal Testing (NIPT)

The non-invasive prenatal test (NIPT) is a prenatal genetic screening test based on the isolation and analysis of fetal DNA that has passed into the mother's blood during pregnancy. In genetics, the condition called "trisomy" refers to the presence of three copies of a chromosome that normally comes in a pair — one from the mother and one from the father. NIPT is generally used to detect extra copies of chromosomes 13 (Patau syndrome), 18 (Edward syndrome) and 21 (Down syndrome), where this disease occurs, as well as excess sex chromosomes, which play a role in sex determination, and microdeletions.

The detection rate of the non-invasive prenatal test for the 3 most common trisomies (having 3 instead of 2 copies of the same chromosome and this causing disease) is 99.5%.

During pregnancy, cell-free DNA (cfDNA) fragments belonging to the fetus circulate in the mother's blood. Fetal cfDNA enters the maternal circulation from the 5th week of pregnancy and its concentration steadily increases in the following weeks. In the NIPT test, circulating cfDNA is used with new-generation sequencing technologies and bioinformatic analyses to detect chromosomal abnormalities in the fetus. For the test to be performed and the results to be reliable, the fraction of fetal cfDNA in the maternal circulation reaches a sufficient level from the 10th week of pregnancy.

This test, which can be performed from the 10th week in singleton pregnancies and from the 12th week in twin pregnancies, is recommended when:

• The mother is 35 years of age or older,
• There is a history of chromosomal abnormality in previous pregnancies,
• There are ultrasonographic findings indicating an increased risk of aneuploidy (numerical chromosomal changes) in the fetus,
• Previous screening results need confirmation,
• There is an increased risk such as previous IVF treatment or a history of recurrent miscarriage,
• There is a history of balanced structural chromosomal abnormality carrier status (translocation, inversion, etc.) (with genetic counseling),
• There are indications identified by your physician.