Table 1 An analysis of characteristics between the case and control groups
Controls | Cases | Chi square | P-values | |
|---|---|---|---|---|
N = 408 (%) | N = 346 (%) | |||
Maternal age (yrs) a | ||||
< 20 | 8 (2.0) | 10 (2.9) | ||
20 ~ 24 | 87 (21.3) | 106 (30.6) | 10.188 | 0.037* |
25 ~ 29 | 193 (47.3) | 145 (41.9) | ||
30 ~ 34 | 83 (20.3) | 62 (17.9) | ||
≥35 | 37 (9.1) | 23 (6.6) | ||
Maternal education level a | ||||
Primary school or less | 1 (0.2) | 12 (3.5) | ||
Junior school | 53 (13.0) | 104 (30.1) | 54.685 | <0.001* |
Senior high school | 106 (26.0) | 86 (24.9) | ||
College or advance | 242 (59.3) | 134 (38.7) | ||
Missing | 6 (1.5) | 9 (2.6) | ||
Residence | ||||
Urban | 331 (81.1) | 215 (62.1) | ||
Suburban | 63 (15.4) | 89 (25.7) | 39.907 | <0.001* |
Rural | 11 (2.7) | 39 (11.3) | ||
Missing | 3 (0.7) | 3 (0.9) | ||
Housing renovation | ||||
Yes | 77 (18.9) | 103 (29.8) | 12.231 | <0.001* |
No | 331 (81.1) | 243 (70.2) | ||
Maternal smoking or exposure to ETS | ||||
Yes | 122 (29.9) | 159 (46.0) | 20.634 | <0.001* |
No | 286 (70.1) | 187 (54.0) | ||
Maternal cooking at home | ||||
Yes | 249 (61.0) | 224 (64.7) | 1.103 | 0.294 |
No | 159 (39.0) | 122 (35.3) | ||
Factory or landfill nearby | ||||
Yes | 75 (18.4) | 100 (28.9) | 11.624 | 0.001* |
No | 333 (81.6) | 246 (71.1) | ||
Folic acid supplements | ||||
Yes | 368 (90.2) | 272 (78.6) | 19.575 | <0.001* |
No | 40 (9.8) | 74 (21.4) | ||
Indoor air ventilation a | ||||
Good | 178 (43.6) | 104 (30.1) | 29.221 | <0.001* |
Average | 215 (52.7) | 203 (58.7) | ||
Poor | 11 (2.7) | 37 (10.7) | ||
Missing | 4 (1.0) | 2 (0.6) | ||
Maternal acute or chronic respiratory disease | ||||
Yes | 192 (47.1) | 185 (53.5) | 2.852 | 0.093 |
No | 214 (52.5) | 161 (46.5) | ||
Missing | 2 (0.5) |