Table 1 Characteristics of subjects in Haikou city, Guangdong Province
From: Ambient air pollution and birth defects in Haikou city, Hainan province
Characteristics | Cases, n (%) | Controls, n (%) | χ 2 | P |
|---|---|---|---|---|
Infant sex | Â | Â | Â | Â |
Male | 261 (51.28%) | 35201 (55.53%) | 3.70 | 0.05 |
Female | 248 (48.72%) | 28190 (44.47%) | Â | Â |
Maternal age (years) | Â | Â | Â | Â |
<20 | 20 (3.78%) | 2419 (3.81%) | 21.75 | <0.01 |
20 ~ 24 | 109 (20.60%) | 15786 (24.85%) | Â | Â |
25 ~ 29 | 195 (36.86%) | 24197 (38.09%) | Â | Â |
30 ~ 34 | 110 (20.79%) | 13707 (21.57%) | Â | Â |
≥35 | 95 (17.96%) | 7424 (11.69%) |  |  |
Gestational age (weeks) | Â | Â | Â | Â |
<37 | 419 (79.21%) | 4217 (6.63%) | 4118.32 | <0.01 |
≥37 | 110 (20.79%) | 59354 (93.37%) |  |  |
Birth weight(g) | Â | Â | Â | Â |
<2500 | 327 (61.81%) | 4070 (6.40%) | 2521.36 | <0.01 |
≥2500 | 202 (38.19%) | 59501 (93.60%) |  |  |
Maternal race | Â | Â | Â | Â |
Han | 516 (97.54%) | 59307 93.29%) | 15.22 | <0.01 |
Other | 13 (2.46%) | 4264 (6.71%) | Â | Â |