Clinical application of noninvasive prenatal testing for the detection of trisomies 21, 18, and 13: a hospital experience

Abstract

Objective: The aim of this study is to report the clinical application of noninvasive prenatal testing (NIPT) to detect chromosomal aneuploidies, especially trisomies 21, 18, and 13 in Chinese singleton pregnancies.

Methods: Pilot validation between NIPT with full karyotyping was conducted blindly on 306 cases. Subsequently, 7705 pregnancies were offered with NIPT. Follow-up data was obtained in all cases.

Results: In the validation stage, a total of five NIPT positive cases were observed for trisomies 21 and 18, and results were confirmed by karyotyping; there were no cases of trisomy 13. Thus, the overall sensitivity and specificity in the validation stage was 100%. In 7705 cases, NIPT results were obtained in 7701 cases; 66 cases were classified as positive, including 48 cases of trisomy 21, 14 cases of trisomy 18, and 4 cases of trisomy 13. Subsequent karyotyping documented two false positive diagnoses for trisomies 21, 18, and 13, respectively. Sensitivity and specificity for detection of trisomies 21 and 18 and 13 were 100% and 99.9%, respectively. Additionally, prenatal chromosomal detection for pregnancies with NIPT has shown a gradual increase since its implementation.

Conclusion: Noninvasive prenatal testing allows a more suitable and efficient workflow for our patients' needs, together with invasive procedures allows a higher prenatal detection of chromosomal aneuploidies.