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Issue: Vol. 561 No. 3 (2026)
Section: Các bài báo
DOI: 10.51298/vmj.v561i3.18593
Date Published: 11/08/2026
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Downloads 24
How to Cite
Triệu, T. S., Đặng, T. S., & Đào, Q. A. (2026). EVALUATION OF NON-INVASIVE PRENATAL TESTING FROM THE 9TH WEEK OF GESTATION IN SINGLETON PREGNANCIES. Vietnam Medical Journal, 561(3). https://doi.org/10.51298/vmj.v561i3.18593

EVALUATION OF NON-INVASIVE PRENATAL TESTING FROM THE 9TH WEEK OF GESTATION IN SINGLETON PREGNANCIES

Tiến Sang Triệu1, , Thái Sơn Đặng2, Quỳnh Anh Đào3
1 Học viện Quân Y
2 Đại học Mở Hà Nội
3 Trường Đại học Kỹ thuật Y tế Hải Dương

Main Article Content

Abstract

Background: Non-invasive prenatal testing (NIPT) using cell-free fetal DNA has high accuracy for common aneuploidies, especially trisomy 13, 18, and 21. In Vietnam, most published studies focused on pregnancies from 10 weeks onward, while data for 9 weeks 0 days to 9 weeks 6 days remain limited.


Objective: To evaluate the feasibility of NIPT at gestational age from 9 weeks 0 days to 9 weeks 6 days and to analyze the relationship between fetal fraction (FF) and gestational age, maternal age, and body mass index (BMI).


Methods: This retrospective study included 2,192 women with singleton pregnancies who underwent NIPT from April 2023 to November 2024 at the Medical Genetics Laboratory, Military Medical University. Data included maternal age, gestational age, BMI, NIPT results, and amniocentesis results in high-risk cases.


Results: Mean maternal age was 30.56 ± 5.05 years, mean BMI was 21.05 ± 2.01 kg/m², and mean gestational age was 9.26 ± 0.20 weeks. The qualified sample rate was 96.26% (2,110/2,192), mean FF was 15.1 ± 4.74%, and the no-call rate was 3.74% (82/2,192). Gestational age in days showed a weak but significant positive association with FF (β = 0.189; p < 0.001), with an increase of about 0.167 percentage points per additional day. No significant differences in FF were found by maternal age (p = 0.299) or BMI (p = 0.421). The positive predictive values of trisomy 21, trisomy 18, trisomy 13, and sex chromosome abnormalities were 100%, 50%, 25%, and 43.6%, respectively. Conclusion: NIPT from the 9th week of pregnancy is highly feasible and shows good screening performance for common aneuploidies, especially trisomy 21.

Keywords

NIPT, cell-free fetal DNA, fetal fraction, 9th week of gestation, trisomy 13, trisomy 18, trisomy 21, prenatal screening

Article Details

References

1. Trần Minh Thắng và cộng sự. Nghiên cứu giá trị của xét nghiệm NIPT dương tính và kết quả chọc ối tại Trung tâm Sản Phụ khoa, Bệnh viện Trung ương Huế. Tạp chí Phụ sản, 2024. 22(5): tr. 30-36.
2. Becking, E.C., et al., Association between low fetal fraction in cell-free DNA screening and fetal chromosomal aberrations: A systematic review and meta-analysis. Prenat Diagn, 2023. 43(7): p. 838-853.
3. Hopkins, M.K., et al., Obesity and no call results: optimal timing of cell-free DNA testing and redraw. Am J Obstet Gynecol, 2021. 225(4): p. 417.e1-417.e10.
4. Hou, Y., et al., Factors affecting cell-free DNA fetal fraction: statistical analysis of 13,661 maternal plasmas for non-invasive prenatal screening. Hum Genomics, 2019. 13(1): p. 62.
5. Hui, L. and D.W. Bianchi, Fetal fraction and noninvasive prenatal testing: What clinicians need to know. Prenat Diagn, 2020. 40(2): p. 155-163.
6. Poulton, A. and L. Hui, Noninvasive prenatal testing: an overview. Aust Prescr, 2025. 48(2): p. 47-53.
7. Shi, Y., et al., Efficiency of Noninvasive Prenatal Testing for Sex Chromosome Aneuploidies. Gynecol Obstet Invest, 2021. 86(4): p. 379-387.
8. Xiang, L., et al., Non-invasive prenatal testing for the detection of trisomies 21, 18, and 13 in pregnant women with various clinical indications: a multicenter observational study of 1,854,148 women in China. Prenat Diagn, 2023. 43(8): p. 1036-1043.