A Paradigm Shift: Considerations in Prenatal Cell-Free DNA Screening

Abstract

Background: Testing to determine the health of a fetus has undergone multiple iterations since the widespread adoption of amniocentesis in the 1970s, including several combinations of ultrasound and/or maternal serum screening. The clinical paradigm for prenatal screening for fetal chromosome aneuploidies was transformed by the introduction of cell-free DNA (cfDNA) screening or noninvasive prenatal screening in 2011. Content: The clinical performance of cfDNA screening is well-established for the most common autosomal and sex chromosome aneuploidies with a detection rate exceeding 90% for all aneuploidies. One of the most significant advantages of cfDNA screening relative to maternal serum screening is the markedly reduced false-positive rate, which is <0.5%. The clinical implementation of cfDNA screening is discussed at length, including key biological, preanalytical, and analytical factors that affect test performance. Summary: cfDNA prenatal screening for whole chromosome aneuploidies has become routine in high-risk obstetric populations. There is tremendous interest in expanding cfDNA screening to the general obstetric population. Early studies suggest that routine application of cfDNA screening is both feasible and effective, although significant economic and quality control considerations remain. IMPACT STATEMENTThe clinical paradigm for screening for fetal chromosomal aneuploidies has been transformed by cell-free DNA (cfDNA) prenatal screening, also called noninvasive prenatal testing. This method sequences DNA from maternal plasma, which contains a mixture of short maternal DNA fragments as well as placental DNA fragments that serve as a fetal surrogate. cfDNA prenatal screening was rapidly adopted in pregnancies at increased risk for trisomy 21, 18, or 13. Due to its low false positive rate, efficacy in the general obstetric population, and ability to detect additional cytogenetic abnormalities, cfDNA prenatal screening is anticipated to become routine in all pregnancies.

Sàng Lọc Trước Sinh Không Xâm Lấn Nipt Và Ứng Dụng Trên 7015 Thai Phụ Tại Trung Tâm Xét Nghiệm Quốc Tế Gentis

“…Sàng lọc trước sinh bao gồm các phương pháp: siêu âm, sàng lọc từ huyết thanh mẹ, và sàng lọc DNA trước sinh không xâm lấn (NIPT). Các phương pháp chẩn đoán dựa vào các quy trình gây xâm lấn nên sẽ tiềm ẩn nguy cơ gây sảy thai, cụ thể là khoảng 0,22 -0,44% đối với chọc ối và 0,1-1% đối với sinh thiết gai nhau [3] Trong các dạng bất thường phát hiện được, thai hội chứng Down có tỷ lệ cao nhất 1,28% (90/7015), tiếp đến là thai mang hội chứng Edwards 0,24% và hội chứng Patau 0,2%. Không phát hiện trường hợp bất thường nào ở nhóm trước 20 và sau 50 tuổi.…”