Table 2 Association between clinical information and the frequency of chromosomal abnormalities
From: Experience of copy number variation sequencing applied in spontaneous abortion
| Â | Normal n (%) | Abnormal n (%) | X2 | P |
|---|---|---|---|---|
Maternal age (years) (N = 650) |  |  | 9.366 | 0.025 |
 ≤ 29 (N = 255) | 105(41.2) | 150(58.8) |  |  |
 30–34 (N = 234) | 83(35.5) | 151(64.5) |  |  |
 35–39 (N = 125) | 41(32.8) | 84(67.2) |  |  |
 ≥ 40 (N = 36) | 6(16.7) | 30(83.3) |  |  |
Previous miscarriage (N = 650) |  |  | 2.051 | 0.562 |
 0 time (N = 198) | 137(46.0) | 161(54.0) |  |  |
 1 times (N = 206) | 91(44.2) | 115(55.8) | ||
 2 times (N = 104) | 44(42.3) | 60(57.7) | ||
 ≥ 3 times (N = 42) | 23(54.8) | 19(45.2) | ||
Gestational age (N = 650) | Â | Â | 11.828 | 0.001 |
 first- trimester (N = 597) | 259(43.4) | 338(56.6) |  |  |
 second- trimester (N = 53) | 36(67.9) | 17(32.1) | ||
Normal live birth history (N = 650) |  |  | 0.045 | 0.831 |
 No(N = 491) | 224(45.6) | 267(54.4) |  |  |
 Yes(N = 159) | 71(44.7) | 88(55.3) | ||
Mode of conception (N = 650) |  |  | 0.437 | 0.509 |
 Natural conception (N = 568) | 255(44.9) | 313(55.1) |  |  |
 Assisted conception (N = 82) | 40(48.8) | 42(51.2) |