Table 2 The incidence of outcomes of interest among Wenchuan exposure and non-exposure group
| Â | No. (Weighted %) | Â | Â | ||
|---|---|---|---|---|---|
Birth outcome | Total | Exposure | Non-exposure | χ2 | P value |
Outcome of delivery | |||||
 Stillbirth | 873 (1.35) | 75 (2.00) | 798 (1.33) | 5.63 | 0.018 |
 Livebirth | 72,580 (98.65) | 3340 (98.00) | 69,240 (98.67) |  |  |
Weeks of gestation | |||||
 Preterm | 6290 (7.55) | 503 (14.14) | 5787 (7.32) | 75.82 | < 0.001 |
 Term | 65,337 (92.01) | 2808 (85.46) | 62,529 (92.24) |  |  |
 Post-term | 250 (0.44) | 17 (0.41) | 233 (0.44) |  |  |
Birth weight | |||||
 Low | 4859 (5.93) | 392 (10.82) | 4467 (5.76) | 47.91 | < 0.001 |
 Normal | 63,658 (87.44) | 2833 (83.77) | 60,825 (87.57) |  |  |
 High | 4728 (6.63) | 174 (5.42) | 4554 (6.67) |  |  |
Birth weight for gestational age | |||||
 Small | 6877 (9.58) | 394 (11.32) | 6483 (9.52) | 4.83 | 0.008 |
 Appropriate | 59,415 (80.86) | 2716 (79.93) | 56,699 (80.89) |  |  |
 Large | 6977 (9.56) | 292 (8.75) | 6685 (9.59) |  |  |