This allows us to know the fetal sex and detects chromosomal trisomies in chromosomes 13, 18 and 21, which correspond to Patau, Edwards and Down syndromes, respectively.

The technique consists of isolating small fragments of free fetal DNA in maternal blood, coming from the placenta, present in maternal blood. And a detailed calculation of the fetal fraction is made, using a double algorithm, discarding samples with less than 3.5% fetal fraction, according to international recommendations.