Table 1.
Patient characteristics per group based on classification of oral glucose tolerance test results
| n (%) | Group 1: non-GDM | Group 2: GDM by WHO 1999 only1 | P value2 | Group 3: GDM by WHO 2013 only | P value2 | Group 4: GDM by both criteria1 | P value2 | |
| n (%) | 3338 | 2119 (63.5) | 137 (4.1) | 576 (17.2) | 506 (15.2) | |||
| Age, yr | 3336 | 32.3 (28.5-35.7) | 34.1 (30.4-38.0) | < 0.001 | 33.0 (29.0-36.7) | 0.002 | 33.6 (30.3-37.0) | < 0.001 |
| Age group, n (%) | 3336 | |||||||
| < 30 yr | 698 (33.0) | 31 (22.6) | 0.002 | 174 (30.2) | 0.031 | 117 (23.1) | < 0.001 | |
| 30-35 yr | 806 (38.1) | 51 (37.2) | 204 (35.4) | 185 (36.6) | ||||
| ≥ 35 yr | 613 (29.0) | 55 (40.1) | 198 (34.4) | 204 (40.3) | ||||
| Prepregnancy BMI, kg/m2 | 3156 | 24.3 (21.8-27.9) | 24.7 (22.7-28.7) | 0.072 | 29.0 (24.5-33.6) | < 0.001 | 28.0 (24.2-32.3) | < 0.001 |
| Prepregnancy BMI group, n (%) | 3156 | |||||||
| < 30 kg/m2 | 1669 (83.7) | 104 (80.6) | 0.598 | 309 (56.6) | < 0.001 | 314 (64.5) | < 0.001 | |
| ≥ 30-< 35 kg/m2 | 207 (10.4) | 18 (14.0) | 133 (24.4) | 102 (20.9) | ||||
| ≥ 35 kg/m2 | 118 (5.9) | 7 (5.4) | 104 (19.0) | 71 (14.6) | ||||
| Ethnicity, n (%) | 3248 | |||||||
| Caucasian | 1126 (54.8) | 69 (51.1) | 0.402 | 292 (51.7) | 0.378 | 241 (48.7) | 0.030 | |
| Mediterranean | 616 (30.0) | 40 (29.6) | 176 (31.2) | 166 (33.5) | ||||
| African, Caribbean | 72 (3.5) | 3 (2.2) | 19 (3.4) | 17 (3.4) | ||||
| Asian | 53 (2.6) | 7 (5.2) | 16 (2.8) | 22 (4.4) | ||||
| Hindustan | 37 (1.8) | 3 (2.2) | 18 (3.2) | 15 (3.0) | ||||
| Other | 150 (7.1) | 13 (9.5) | 44 (7.6) | 34 (6.7) | ||||
| Gravidity | 3336 | 2 (1-3) | 2 (1-3) | 0.368 | 2 (2-4) | < 0.001 | 2 (2-3) | 0.045 |
| Parity, n (%) | 3323 | |||||||
| 0 | 803 (37.9) | 46 (33.6) | 0.102 | 171 (29.7) | < 0.001 | 169 (33.4) | 0.010 | |
| 1 | 785 (37.0) | 48 (35.0) | 231 (40.1) | 183 (36.2) | ||||
| ≥ 2 | 519 (24.9) | 43 (31.4) | 173 (30.0) | 152 (30.0) | ||||
| Smoking during pregnancy, n (%) | 3270 | 277 (13.3) | 15 (11.1) | 0.470 | 94 (16.8) | 0.031 | 79 (16.1) | 0.104 |
| Conception spontaneous, n (%) | 3277 | 1866 (89.8) | 120 (88.9) | 0.748 | 496 (87.9) | 0.216 | 431 (86.4) | 0.029 |
| Multiple pregnancy, n (%) | 3336 | 84 (4.0) | 9 (6.6) | 0.138 | 10 (1.7) | 0.010 | 33 (6.5) | 0.012 |
| Gestational age at OGTT, wk | 3336 | 27.1 (25.1-29.6) | 28.1 (25.4-32.7) | 0.041 | 27.0 (24.6-29.1) | < 0.001 | 27.0 (23.9-29.7) | < 0.001 |
| OGTT fasting plasma glucose value, mmol/L | 3336 | 4.6 (4.4-4.8) | 4.7 (4.5-4.8) | 0.087 | 5.2 (5.1-5.4) | < 0.001 | 5.4 (5.0-5.8) | < 0.001 |
| OGTT 2-h post load glucose value, mmol/L | 3298 | 5.7 (4.9-6.4) | 8.0 (7.8-8.2) | < 0.001 | 6.4 (5.7-6.9) | < 0.001 | 8.7 (8.1-9.6) | < 0.001 |
Continuous variables are presented as mean ± SD or median (interquartile range). Percentages may not add up to 100% due to rounding.
1
Women in this group received treatment for gestational diabetes mellitus.
2
P value reported compared to group 1: non-gestational diabetes mellitus.
GDM: Gestational diabetes mellitus; BMI: Body mass index; OGTT: Oral glucose tolerance test; WHO: World Health Organization.