Detection of fetal cell-free DNA in maternal plasma for Down syndrome, Edward syndrome and Patau syndrome of high risk fetus

Abstract

Objective: The study aimed to validate the efficacy of detection of fetal cell-free DNA in maternal plasma of trisomy 21, 18 and 13 in a clinical setting.

Methods: A total of 2340 women at high risk for Down syndrome based on maternal age, prenatal history or a positive sesum or sonographic screening test were offered prenatal noninvasive aneuploidy test. According to the prenatal noninvasive aneuploidy test, the pregnant women at high risk were offered amniocentesis karyotype analysis and the pregnant at low risk were followed up to make sure the newborn outcome.

Results: The prenatal noninvasive aneuploidy test was positive for trisomy 21 in 17 cases, for trisomy 18 in 6 cases and for trisomy 13 in 1 case, which of all were confirmed by karyotype analysis. Newborns of low risk gestational woman detected by prenatal noninvasive aneuploidy for trisomy 21, 18, 13 were followed up and no one was found with trisomy.

Conclusions: The prenatal noninvasive aneuploidy test is highly accurate for detection of trisomy 21, 18 and 13, which can be considered as a practical alternative for traditional invasive diagnostic procedures.

Keywords: Down syndrome; fetal cell-free DNA; prenatal noninvasive diagnosis.

Figure 1

The flow chart of noninvasive prenatal testing for T21, T18 and T13 using DNA.

Figure 2

The results of noninvasive prenatal testing using fetal cell-free fetal DNA in 2340 pregnant women. A: Trisomy 13; B: Trisomy 18; C: Trisomy 21. The yellow and purple points represents T-score of pregnant women, red point indicates T-score of pregnant women with high risk of Trisomy 13, 18, 21.