Role of cell-free fetal DNA in the maternal plasma in the prenatal diagnosis of chromosomal abnormalities

Objective: This study aimed to investigate the role of cell-free fetal DNA (cff-DNA) in the maternal plasma in the prenatal diagnosis of chromosomal abnormalities. Methods: The results of cell-free DNA detection of maternal plasma were retrospectively reviewed in 1440 pregnant women, and the pregnancy outcomes were followed up. Results: (1) Of 1440 pregnant women, 20 had a high risk for trisomy 21, and invasive prenatal examination showed the karyotype of 47, XN, +21; 22 had a high risk for trisomy 18, invasive prenatal examination in 19 women showed the karyotype of 47, XN, +18, but 3 women did not receive karyotyping. (2) When the cut-off value was 1/750, both the sensitivity and detection rates were 100% in the screening of trisomy. (3) Fetal chromosomal aneuploidy was significantly associated with NT thickening, AFP MOM, β-HCG MOM (≥3.5) and apparent ultrasound structural abnormalities (P<0.05). Conclusion: The cff-DNA detection is a fast, safe and high-throughput method for the prenatal examination of fetal chromosomal abnormalities. It is expected to replace the invasive prenatal diagnostic techniques and bring good prospects for the non-invasive prenatal diagnosis.