Table 1.
Characteristics of the study population according to gestational diabetes mellitus.
| Characteristics | Non-GDM (N = 14,159) | GDM (N = 2,986) | ALL | P-value |
|---|---|---|---|---|
| Urban,% | 10,609 (74.93) | 2,246 (75.22) | 12,855 (74.98) | 0.74 |
| Age, mean (SD), year | 29.93 ± 4.56 | 31.49 ± 4.72 | 30.20 ± 4.62 | <0.0001 |
| Age group, year | ||||
| <30 | 6,952 (49.10) | 1,093 (36.60) | 8,045 (46.92) | <0.0001 |
| 30-34 | 4,829 (34.11) | 1,064 (35.63) | 5,893 (34.37) | |
| ≥35 | 2,378 (16.79) | 829 (27.76) | 3,207 (18.71) | |
| Education level | ||||
| Low | 175 (1.24) | 45 (1.51) | 220 (1.28) | 0.0001 |
| Medium | 5,719 (40.39) | 1,322 (44.27) | 7,041 (41.07) | |
| High | 8,265 (58.37) | 1,619 (54.22) | 9,884 (57.65) | |
| Occupational physical activity | ||||
| Light | 8,466 (59.79) | 1,712 (57.33) | 10,178 (59.36) | <0.0001 |
| Moderate | 4,254 (30.04) | 887 (29.71) | 5,141 (29.99) | |
| Active | 1,439 (10.16) | 387 (12.96) | 1,826 (10.65) | |
| Pre-pregnancy BMI, mean (SD), kg/m2 | 22.22 ± 3.47 | 23.40 ± 3.70 | 22.43 ± 3.54 | <0.0001 |
| Pre-pregnancy BMI group, kg/m2 | ||||
| <25 | 11,476 (81.05) | 2,078 (69.59) | 13,554 (79.06) | 0.0001 |
| 25–30 | 2,239 (15.81) | 741 (24.82) | 2,980 (17.38) | |
| ≥30 | 444 (3.14) | 167 (5.59) | 611 (3.56) | |
| BMI at 15–20 weeks gestation, kg/m2 | ||||
| <25 | 10,117 (73.93) | 1,730 (59.19) | 11,847 (71.33) | <0.0001 |
| 25–30 | 2,930 (21.41) | 938 (32.09) | 3,868 (23.29) | |
| ≥30 | 638 (4.66) | 255 (8.72) | 893 (5.38) | |
| BMI gain from pre-pregnancy to 15–20 weeks gestation | 0.8 (0.1–1.6) | 1.0 (0.3–1.8) | 0.8 (0.2–1.6) | <0.0001 |
| Parity≥1,% | 7,282 (51.43) | 1,739 (58.24) | 9,021 (52.62) | <0.0001 |
| Assisted reproduction,% | 156 (1.10) | 62 (2.08) | 218 (1.27) | <0.0001 |
| History of previous GDM,% | 231 (2.65) | 322 (17.09) | 553 (5.22) | <0.0001 |
| Cigarette smokers, % | ||||
| Habitual smoker before pregnancy | 86 (0.61) | 25 (0.84) | 111 (0.65) | 0.15 |
| Habitual smoker during pregnancy | 20 (0.14) | 8 (0.27) | 28 (0.16) | 0.13 |
| Alcohol drinkers, % | ||||
| Alcohol drinker before pregnancy | 240 (1.70) | 56 (1.88) | 296 (1.73) | 0.49 |
| Alcohol drinker during pregnancy | 31 (0.22) | 10 (0.33) | 41 (0.24) | 0.24 |
| Husband smoking before pregnancy,% | 5,266 (37.19) | 1,101 (36.87) | 6,367 (37.14) | 0.74 |
| Husband drinking before pregnancy,% | 4,604 (32.52) | 1,006 (33.69) | 5,610 (32.72) | 0.21 |
| Dietary patterns | ||||
| Well-balanced diet | 12,074 (85.30) | 2,648 (88.74) | 14,722 (85.90) | <0.0001 |
| Eat less vegetables | 396 (2.80) | 80 (2.68) | 476 (2.78) | |
| Eat less meat | 1,684 (11.90) | 256 (8.58) | 1,940 (11.32) | |
| Folic acid supplements,% | 13,264 (93.68) | 2,795 (93.60) | 16,059 (93.67) | 0.88 |
| Co-morbidities | ||||
| Anemia | 377 (2.66) | 54 (1.81) | 431 (2.51) | 0.0067 |
| Thyroid diseases | 462 (3.26) | 116 (3.88) | 578 (3.37) | 0.09 |
Data are presented as means ± SD, median (IQR) or n (%). Variables with statistical significance were shown in boldface.