Table 7:

NIPT Failure Rate

Author, Year	Initial NIPT Test	Repeat NIPT Test	True Status Among Failures
Bianchi et al, 201452	0.9% (18/1,970) 50% (9/18) during cell-free DNA extraction 50% (9/18) during sequencing No clear reason for failures	None	Not reported
Langlois et al, 201754	0.9% (11/1,165) 90.9% (10/11) low fetal fraction 9.1% (1/11) unusually high variance in cell-free DNA count	Repeat NIPT test: 45.5% (5/11) success	3/11 triploidy 3/11 normal
Nicolaides et al, 201255	4.9% (100/2,049) 46.0% (46/100) low fetal fraction 54.0% (54/100) assay failure	None	Not reported
Norton et al, 201556	3.0% (488/16,329) 39.3% (192/488) low fetal fraction 17.0% (83/488) fetal fraction could not be measured 43.6% (213/488) high assay variance or failure	None	13/488 aneuploidy
Palomaki et al, 201757	5.6% (150/2,681) 93.3% (140/150) complete test failure 6.7% (10/150) partial test failure	Repeat NIPT test: 76.5% (65/85) success	0 trisomy 21, 18, or 13
Quezada et al, 201558	4.2% (123/2,905) 30.9% (38/123) low fetal fraction 12.2% (15/123) assay failure 0.8% (1/123) sample not received by laboratory	Repeat NIPT test: 62.7% (69/110) success	49/54 normal 2/54 trisomy 21 3/54 pregnancy loss with no karyotype
Song et al, 201359	3.8% (73/1,916) 65.8% (48/73) failed DNA quality control 34.2% (25/73) failed sequencing quality control	None	Not reported

Abbreviation: NIPT, noninvasive prenatal testing.