Table 1. Characteristics of the participants according to gestational diabetes.
| Characteristics | GDM | P | |
| Yes | No | ||
| N = 1,030 | N = 5,978 | ||
| Age, years, mean (SD) | 29.6 (3.9) | 28.3 (3.4) | <0.001 |
| Pre-pregnancy BMI, kg/m2, mean (SD) | 21.5 (3.1) | 20.6 (2.7) | <0.001 |
| Education | |||
| Middle school or below (%) | 132 (12.8) | 514 (8.6) | <0.001 |
| High school (%) | 193 (18.7) | 1012 (16.9) | |
| College or above (%) | 705 (68.4) | 4451 (74.5) | |
| Annual household income (Yuan)* | |||
| <50,000 (%) | 421 (41.9) | 2311 (39.3) | 0.130 |
| 50,000–100,000 (%) | 417 (41.5) | 2459 (41.8) | |
| >100,000 (%) | 167 (16.6) | 1117 (19.0) | |
| Cigarette smoking status | |||
| Current or ever smokers (%) | 9 (0.9) | 30 (0.5) | 0.138 |
| Never smokers (%) | 1021 (99.1) | 5948 (99.5) | |
| Passive smoking exposure | |||
| Yes (%) | 211 (20.5) | 1274 (21.3) | 0.549 |
| No (%) | 819 (79.5) | 4704 (78.7) | |
| Alcohol drinking | |||
| Yes (%) | 22 (2.1) | 129 (2.2) | 0.964 |
| No (%) | 1008 (97.9) | 5849 (97.8) | |
BMI, body mass index; GDM, gestational diabetes mellitus; SD, standard deviation.
*One Yuan RMB is equal to 0.1462 United States dollars.