This product is designed for the qualitative test of the cell-free fetal DNA in the plasma of pregnant women who are pregnant with a single fetus, whose gestational age are between 8 weeks and 24 weeks, and whose risks of giving birth to a baby with chromosomal aneuploidies are high. By analyzing the differences in the quantities of chromosomes 21, 18, and 13 between the cell-free fetal DNA in the specimens and the normal human DNA, it helps doctors make prenatal diagnosis of 21-trisomy syndrome, 18-trisomy syndrome, and 13-trisomy syndrome.
Chromosomal aneuploidy refers to an increase or decrease in the number of one or more chromosomes relative to the normal number of 46 for a human being. It is closely related to incidence of diseases in and mortality of infants and young children. It is recommended that pregnant women with high risks of giving birth to a baby with chromosomal aneuploidies undergo prenatal diagnosis following the doctors’ instructions. Women with high risk of givingbirth to a baby with chromosomal aneuploidies include 1) those whose ages are above 35; 2) those whose risks of giving birth to a baby with chromosomal aneuploidies turn out to be high in prenatal screenings; 3) those who gave birth to a baby with chromosomal aneuploidies in the past; 4) those who are suspected of being pregnant with a fetus with chromosomal aneuploidies in B-ultrasonography; 5) those who are with chromosomal aneuploidies or whose husbands are with chromosomal aneuploidies; and 6) those whose risks of giving birth to a baby with chromosomal aneuploidies are considered as high by the doctors. Currently, prenatal diagnosis of fetal chromosomal aneuploidies is realized via chromosome karyotype analysis of cultured amniotic fluid cells collected through amniotic fluid puncture guided by B-ultrasonography. It provides accurate results; yet it is time-consuming and might lead to significant reduction in the quantity of amniotic fluid which would result in fetal distress.