| Total | Overall adverse pregnancy outcomes | χ2 | P | |
---|---|---|---|---|---|
N (%) | Case(N = 63) | Control(N = 237) | |||
Age | |||||
  ≤ 25 | 25 (8.3) | 1 (1.6) | 24 (10.1) | 16.957 | 0.001* |
 26–30 | 173 (57.7) | 31 (49.2) | 142 (59.9) |  |  |
 31–35 | 77 (25.7) | 19 (30.2) | 58 (24.5) |  |  |
  > 35 | 25 (8.3) | 12 (19.0) | 13 (5.5) |  |  |
Residence | |||||
 suburb/rural | 276 (92.0) | 54 (85.7) | 222 (93.7) | 4.281 | 0.041* |
 city | 24 (8.0) | 9 (14.3) | 15 (6.3) |  |  |
Education | |||||
 junior high school or below | 19 (6.3) | 12 (11.1) | 12 (5.1) | 3.176 | 0.204 |
 senior high school or graduate | 126 (42.0) | 102 (38.1) | 102 (43.0) |  |  |
 undergraduate or above | 155 (50.7) | 123 (50.8) | 123 (51.9) |  |  |
Economic situation a (per month) | |||||
 poor level | 33 (10.7) | 10 (15.9) | 23 (11.0) | 1.162 | 0.559 |
 moderate level | 217 (73.7) | 44 (69.8) | 173 (73.0) |  |  |
 good level | 50 (15.6) | 9 (14.3) | 34 (16.0) |  |  |
Occupation | |||||
 peasants | 19 (6.3) | 6 (9.5) | 13 (5.5) | 1.368 | 0.242 |
 others | 281 (93.7) | 57 (90.5) | 224 (94.5) |  |  |
Smoking | |||||
 yes | 5 (1.67) | 3 (4.8) | 2 (0.8) | 4.662 | 0.031* |
 no | 295 (98.3) | 60 (95.2) | 235 (99.2) |  |  |
Alcohol intake | |||||
 yes | 8 (2.7) | 5 (7.9) | 3 (1.3) | 8.553 | 0.003* |
 no | 292 (97.3) | 58 (92.1) | 234 (98.7) |  |  |