Table 1 Basic characteristics of the 12 included literatures
Id | Author | Year | Country | Study design | Sample size | Mean diagnostic gestational week | TP | FP | FN | TN |
|---|---|---|---|---|---|---|---|---|---|---|
1 | Crombleholme [8] | 2002 | North America | Prospective | 58 | NR | 12 | 4 | 7 | 35 |
2 | Cass [9] | 2011 | North America | Retrospective | 78 | 21.7 ± 4.5 | 11 | 11 | 1 | 55 |
3 | Yong [12] | 2012 | North America | Retrospective | 69 | 21 | 4 | 6 | 2 | 57 |
4 | Ehrenberg-Buchner [13] | 2013 | North America | Retrospective | 62 | 24.3 | 3 | 2 | 1 | 56 |
5 | Zhang [14] | 2014 | Asia | Retrospective | 68 | 24 | 7 | 5 | 0 | 56 |
6 | Stoiber [15] | 2017 | Europe | Retrospective | 34 | 24.2 ± 4.7 | 3 | 5 | 5 | 21 |
7 | An [19] | 2017 | Asia | Retrospective | 88 | NR | 39 | 5 | 3 | 41 |
8 | Zhang [16] | 2016 | Asia | Retrospective | 84 | 24 | 12 | 4 | 2 | 66 |
9 | Chen [20] | 2014 | Asia | Retrospective | 75 | 24 | 7 | 6 | 0 | 62 |
10 | Hu [21] | 2017 | Asia | Retrospective | 82 | 26.2 ± 6.5 | 4 | 7 | 1 | 70 |
11 | Zhang [22] | 2017 | Asia | Retrospective | 74 | 28 | 5 | 3 | 0 | 66 |
12 | Ma [23] | 2017 | Asia | Retrospective | 35 | NR | 3 | 6 | 0 | 26 |