Table 4 Influencing factors of NIPS detection efficiency
Factors | Prenatal diagnosis by CMA | PPV (%) | p value | ||
|---|---|---|---|---|---|
n | TP | FP | |||
CNVs characteristic | |||||
Segment gains | 69 | 26 | 43 | 37.7 | 0.782 |
Segment losses | 27 | 11 | 16 | 40.7 | |
CNVs size | |||||
< 3 Mb | 39 | 19 | 20 | 48.7 | 0.170 |
3 Mb ~ 5 Mb | 29 | 12 | 17 | 41.4 | |
5 Mb ~ 10 Mb | 7 | 3 | 4 | 42.9 | |
> 10 Mb | 21 | 3 | 18 | 14.3 | |
Fetal fraction | |||||
< 10% | 33 | 9 | 24 | 27.3 | 0.101 |
≥ 10% | 63 | 28 | 35 | 44.4 | |
Unique reads | |||||
< 3 Mb | 52 | 18 | 34 | 34.6 | 0.762 |
3 Mb ~ 4 Mb | 36 | 15 | 21 | 41.7 | |
> 4 Mb | 8 | 4 | 4 | 50.0 | |
CNVs Z-score | |||||
Within 3 | 68 | 32 | 36 | 47.1 | 0.007 |
Beyond 3 | 28 | 5 | 23 | 17.9 | |
Chromosome grouping | |||||
A group (chr 1,2,3) | 15 | 9 | 6 | 60.0 | 0.021 |
B group (chr 4,5) | 16 | 8 | 8 | 50.0 | |
C group (chr 6,7,8,9,10,11,12) | 21 | 1 | 20 | 4.8 | |
D group (chr 13,14,15) | 14 | 6 | 8 | 42.9 | |
E group (chr 16,17,18) | 17 | 7 | 10 | 41.2 | |
F group (chr 19,20) | 2 | 1 | 1 | 50.0 | |
G group (chr 21,22) | 11 | 5 | 6 | 45.5 | |