Table 1.
Baseline characteristics of participants
| Variables | Ha Noi (n1=905) | Hai Phong (n2=298) | Ho Chi Minh (n3=827) | Total (n=2030) |
| n (%) | n (%) | n (%) | n (%) | |
| Age (years) | ||||
| <25, (n (%) | 346 (38.2) | 97 (32.6) | 194 (23.5) | 637 (31.4) |
| 25–35, n (%) | 499 (55.1) | 178 (59.7) | 553 (66.9) | 1230 (60.6) |
| >35, n (%) | 60 (6.6) | 23 (7.7) | 80 (9.7) | 163 (8.0) |
| Mean (SD) | 26.6 (5.0) | 27.4 (5.4) | 28.6 (5.3) | 27.6 (5.3) |
| Marital status (married) | 902 (99.7) | 294 (98.7) | 819 (99.0) | 2015 (99.3) |
| Occupation | ||||
| Famers | 194 (21.4) | 44 (14.8) | 58 (7.0) | 296 (14.6) |
| Workers | 303 (33.5) | 139 (46.6) | 376 (45.5) | 818 (40.3) |
| Office and technical staff | 226 (25.0) | 44 (14.8) | 186 (22.5) | 456 (22.5) |
| Sales worker | 35 (3.9) | 10 (3.4) | 74 (8.9) | 119 (5.9) |
| Housewife/unemployed | 147 (16.2) | 61 (20.5) | 133 (16.1) | 341 (16.8) |
| Educational level | ||||
| Under secondary | 15 (1.7) | 3 (1.0) | 153 (18.5) | 171 (8.4) |
| Secondary | 164 (18.1) | 98 (32.9) | 289 (34.9) | 551 (27.1) |
| High school | 265 (29.3) | 88 (29.5) | 172 (20.8) | 525 (25.9) |
| College/university | 461 (50.9) | 109 (36.6) | 213 (25.8) | 783 (38.6) |
| Parity | ||||
| 0 | 361 (39.9) | 105 (35.2) | 323 (39.1) | 789 (38.9) |
| 1 | 306 (33.8) | 110 (36.9) | 340 (41.1) | 756 (37.2) |
| ≥2 | 238 (26.3) | 83 (27.9) | 164 (19.8) | 485 (23.9) |
| Body mass index (BMI) before pregnancy (kg/m2)* (n=2010) | ||||
| Low (<18.5) | 244 (27.0) | 88 (31.7) | 177 (21.4) | 509 (25.3) |
| Normal (18.5 -<23.0) | 587 (64.9) | 178 (64.0) | 478 (57.8) | 1243 (61.8) |
| High (≥23.0) | 74 (8.2) | 12 (4.3) | 172 (20.8) | 258 (12.8) |
| Mean (SD) | 19.8 (2.3) | 19.5 (2.2) | 20.8 (2.8) | 20.2 (2.6) |
| History of previous pregnancy (n=1241) | ||||
| GDM | 1 (0.2) | 1 (0.5) | 15 (3.0) | 17 (1.4) |
| Hypertension | 0 (0.0) | 0 (0.0) | 4 (0.8) | 4 (0.3) |
| Pre-eclampsia | 4 (0.7) | 0 (0.0) | 3 (0.6) | 7 (0.6) |
| Preterm birth | 43 (7.9) | 8 (4.1) | 27 (5.4) | 78 (6.3) |
| Macrosomia | 29 (5.3) | 4 (2.1) | 12 (2.4) | 45 (3.6) |
| Birth defects | 13 (2.4) | 3 (1.6) | 6 (1.2) | 22 (1.8) |
| Caesarean section | 135 (24.8) | 18 (9.3) | 114 (22.6) | 267 (21.5) |
| Stillbirth | 100 (11.1) | 37 (12.4) | 75 (9.1) | 212 (10.4) |
| Abortion | 207 (22.9) | 46 (15.4) | 110 (13.3) | 363 (17.9) |
| History of participant’s family | ||||
| Diabetes | 38 (4.2) | 6 (2.0) | 84 (10.2) | 128 (6.3) |
| Hypertension | 74 (8.2) | 36 (12.1) | 197 (23.8) | 307 (15.1) |
| Smoking and drinking during pregnancy | ||||
| Active smoking | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
| Passive smoking | 481 (53.1) | 150 (50.3) | 439 (53.1) | 1070 (52.7) |
| Drinking | 163 (18.0) | 29 (9.7) | 80 (9.7) | 272 (13.4) |
| Blood glucose test (n=2023) | ||||
| Fasting (mean, SD) | 4.4 (0.5) | 4.4 (0.7) | 4.5 (0.4) | 4.5 (0.5) |
| 1-Hour 75 g OGTT (mean, SD) | 7.2 (1.8) | 6.9 (1.6) | 8.4 (1.8) | 7.6 (1.9) |
| 2-Hour 75 OGTT (mean, SD) | 6.4 (1.5) | 6.1 (1.3) | 7.3 (1.5) | 6.7 (1.6) |
| Hyperglycaemia† | 148 (16.4) | 59 (19.9) | 255 (31.0) | 462 (22.8) |
| Blood pressure | ||||
| Systolic, mm Hg (mean, SD) | 105.0 (7.3) | 107.0 (8.3) | 105.8 (9.0) | 105.6 (8.2) |
| Diastolic, mm Hg (mean, SD) | 64.9 (6.4) | 64.3 (6.1) | 71.3 (7.3) | 67.4 (7.5) |
| Pulse, bpm (mean, SD) | 84.3 (9.3) | 79.3 (6.0) | 97.0 (9.9) | 88.7 (11.5) |