Non-Invasive Prenatal Test (NIPT) is a prenatal genetic screening test based on the isolation and analysis of fetal DNA that is present in the maternal bloodstream during pregnancy. In genetics, a condition called “trisomy” refers to the presence of three copies of a chromosome—normally, one from the mother and one from the father—instead of the usual two. NIPT is typically used to detect extra chromosomes on the 13th (Patau Syndrome), 18th (Edwards Syndrome), and 21st (Down Syndrome) chromosomes, as well as to determine sex chromosome aneuploidies and certain microdeletions.

The detection rate of NIPT for the three most common trisomies (where there are three copies of a chromosome instead of two, causing disease) is 99.5%.

During pregnancy, cell-free DNA (cfDNA) fragments from the fetus circulate in the maternal blood. Fetal cfDNA enters maternal circulation from the 5th week of gestation and increases in concentration over subsequent weeks. Using next-generation sequencing technologies and bioinformatic analyses, NIPT allows detection of chromosomal abnormalities in the fetus. For accurate testing and reliable results, a sufficient proportion of fetal cfDNA must be present in maternal blood, which is typically reached from the 10th week of gestation.

This test can be performed from the 10th week for singleton pregnancies and from the 12th week for twin pregnancies and is recommended in cases such as:

• Maternal age of 35 years or older,

• History of chromosomal abnormalities in previous pregnancies,

• Ultrasound findings indicating increased risk of fetal aneuploidy,

• Confirmation of previous screening results,

• Prior in vitro fertilization treatment or history of recurrent miscarriage,

• History of balanced structural chromosomal abnormalities (such as translocation or inversion) with genetic counseling,

• Other indications deemed necessary by your physician.