Thus, non-invasive prenatal tests are tests performed before the baby is born to detect abnormalities and do not involve any intervention on the foetus. Information about the baby is obtained through free foetal DNA in the mother’s blood.

They are the most complete non-invasive prenatal tests that exist today: with a simple test of the mother’s blood, they can detect in the future baby the presence of anomalies of chromosomes 21, 18 and 13 (Down, Edwards and Patau syndrome) and the most common anomalies generated by sex chromosomes (X and Y).

There are also more advanced versions of the free DNA in blood test that incorporate the detection of abnormalities of other chromosomes, mainly related to miscarriages in the first trimester, and that can identify losses of a fragment of certain chromosomes – disorders known as microdeletions – related to important genetic syndromes. These extended versions are requested when medically indicated in those cases in which certain abnormalities are detected by ultrasound.

In which cases are they indicated?

• Women who wish to rule out the most frequent chromosomal abnormalities.
• Women with high risk of chromosomal abnormalities after first trimester screening (hormonal and ultrasound analysis).
• Women with a previous pregnancy with chromosomal abnormality (e.g., Down syndrome).
• Women for whom ultrasound abnormalities have been detected that lead us to suspect a chromosomal abnormality.

In what cases is it indicated?

• Women who wish to rule out the most frequent chromosomal abnormalities.
• Women with high risk of chromosomal abnormalities after first trimester screening (hormonal and ultrasound analysis).
• Women with a previous pregnancy with chromosomal abnormality (e.g., Down syndrome).
• Women for whom ultrasound abnormalities have been detected that lead us to suspect a chromosomal abnormality.

Steps to follow to perform a non-invasive prenatal test

From the 10^th week of pregnancy, a blood sample is collected from the expectant mother, which we send to the laboratory. For the study of chromosomes 21, 18, 13 and sex chromosomes, the results are ready in just three working days and our specialists can explain the results to you. In the case of the non-invasive prenatal test to detect alterations in all chromosomes and microdeletions, the results are available in 10 days.