Cell-free fetal DNA testing and its correlation with prenatal indications

Table 2 The performance of NIPT for detection of fetal aneuploidy

NIPT result (N = 14,316)	Positive(n)	TP(n)	FN(n)	Sensitivity	Specificity	PPV	NPV
T21	49	45	1	97.83%	99.97%	91.84%	99.99%
T18	16	11	0	100.00%	99.99%	68.75%	100.0%
T13	16	6	0	100.00%	99.96%	37.50%	100.0%
XO	29	22	0	100.00%	99.96%	75.86%	NA
XXY	16	8	0	100.00%	99.96%	50.00%	NA
XYY	9	5	0	100.00%	99.98%	55.56%	NA
XXX	9	3	0	100.00%	99.96%	33.33%	NA
CNV	14	2	NA	–	–	14.29%	NA
other autosomal aneuploidy abnormalities	31	2	NA	–	–	6.45%	NA
Total	189	104		–	–	55.03%	NA

Since sex chromosome abnormalities and CNV abnormalities may not appear clinically during follow-up, it is impossible to calculate false negatives or false positives, so sensitivity and specificity are not calculated
NPV negative predictive value, PPV positive predictive value, Positive the NIPT(+), TP true positive, both NIPT(+) and interventional prenatal diagnosis (+), FN false negative, PPV positive predictive value, NPV negative predictive value

ISSN: 1471-2393