Table 1 Distribution of characteristics among participants
Variables | Pregnant women in their first pregnancy (n, %) | Pregnant women in their second pregnancy (n, %) | χ2/t | p value |
|---|---|---|---|---|
Nationality | ||||
 Han | 1020 (93.2) | 464 (92.1) |  |  |
 Minority | 74 (6.8) | 40 (7.9) | 0.716 | 0.398 |
Maternal age (years) | Â | Â | 2.207 | 0.027* |
Single-child | ||||
 Yes | 354 (32.4) | 103 (20.4) |  |  |
 No | 740 (67.6) | 401 (79.6) | 24.016 | 0.000*** |
Marital status | ||||
 Unmarried | 9 (0.8) | 3 (0.6) |  |  |
 Married | 1078 (98.5) | 498 (98.8) |  |  |
 Divorced or widowhood | 7 (0.7) | 3 (0.6) |  |  |
Education level | ||||
 Basic | 116 (10.6) | 81 (16.1) |  |  |
 Secondary | 102 (9.3) | 54 (10.7) |  |  |
 Higher | 876 (80.1) | 369 (73.2) | 11.136 | 0.004** |
Location | ||||
 Lanzhou | 863 (78.9) | 389 (77.2) |  |  |
 Chongqing | 231 (21.1) | 115 (22.8) | 0.589 | 0.443 |
Residence | ||||
 Urban | 951 (86.9) | 444 (88.1) |  |  |
 Rural | 143 (13.1) | 60 (11.9) | 0.623 | 0.515 |
The per capita income of the family | ||||
 < 4500¥ | 450 (41.1) | 208 (41.2) |  |  |
 4500¥ to 9000¥ | 506 (46.3) | 214 (42.5) |  |  |
 > 9000¥ | 133 (12.6) | 82 (16.3) | 5.424 | 0.066 |