Non-invasive prenatal screening (NIPT) is a genetic test reserved for pregnant women whose fetuses present a risk of trisomy 13, 18 or 21. It notably makes it possible to reduce the number of invasive procedures, such as amniocentesis. How is it going? What are the risks ? We take stock.
Non-invasive prenatal screening (NIPT) is a prenatal screening technique that detects chromosome abnormalities in the fetus. Performed in the form of a simple blood test during the first trimester of pregnancy, it reduces the number of amniocentesis and trophoblast biopsies. Today, it is totally systematically offered to pregnant women as part of prenatal screening, and covered by health insurance.
When to do the NIPT test? Who can benefit ?
As a reminder, during the first trimester of pregnancy, the probability that the fetus has trisomy 21 is assessed based on the combination of three factors:
the the determination of serum markers in the blood (a substance secreted by the fetus);
nuchal translucency measurement, the small space behind the neck (if this space is too large, it may be a sign of a chromosomal abnormality)
and and the age of the future mother, since the risk increases with age age.
Once these three factors are combined, we obtain a probability marker located in one of the following ranges:
if if your risk is less than 1/1000: the screening stops there;
if if your risk is greater than or equal to 1/50: you are directly offered amniocentesis
but but if your risk is between 1/1000 and 1/51: this is where we can consider non-invasive prenatal screening.
NIPT can be performed from the 12th week of amenorrhea (absence of menstruation) and throughout pregnancy, after performing the first trimester ultrasound. If it is optional, it must be offered by doctors or midwives to the pregnant woman, who decides – or not – to submit it.
