Table 1.
The baseline characteristics of the study participants.
| Characteristics | Patients (n = 49,611) | Controls (n = 137,821) | p* |
|---|---|---|---|
| During the 8th to 12th gestational weeks | |||
| Age (years) | 29.33 (4.88) | 28.34 (4.45) | < 0.001 |
| Pre-pregnancy body mass index (kg/m2) | 20.81 (19.10–23.01) | 20.13 (18.73–22.04) | < 0.001 |
| Age at menarche (years) | 14 (13–15) | 14 (13–15) | 0.049 |
| Alcohol drinking | 20 (0.04%) | 72 (0.05%) | 0.294 |
| Cigarette smoking | 8 (0.02%) | 33 (0.02%) | 0.306 |
| High education | 11,771 (23.73%) | 36,067 (26.17%) | < 0.001 |
| Maternal family history of diabetes mellitus | 1790 (3.61%) | 3498 (2.54%) | < 0.001 |
| Maternal family history of hypertension | 3200 (6.45%) | 8725 (6.33%) | 0.496 |
| Hypertension | 120 (0.24%) | 224 (0.16%) | < 0.001 |
| Pre-pregnancy intake of folic acid | 49,444 (99.66%) | 137,494 (99.76%) | < 0.001 |
| Hemopathy | 110 (0.22%) | 319 (0.23%) | 0.663 |
| Epilepsy | 17 (0.03%) | 58 (0.04%) | 0.444 |
| Hyperthyroidism | 446 (0.9%) | 1306 (0.95%) | 0.29 |
| Cardiovascular diseases | 125 (0.25%) | 304 (0.22%) | 0.228 |
| Liver diseases | 2468 (4.97%) | 6903 (5.01%) | 0.603 |
| Kidney diseases | 153 (0.31%) | 524 (0.38%) | 0.019 |
| Lung diseases | 103 (0.21%) | 283 (0.21%) | 0.959 |
| Hemoglobin (g/L) | 124 (117–131) | 124 (117–130) | 0.477 |
| White cell count (109/L) | 8.50 (7.26–9.91) | 8.11 (6.96–9.48) | < 0.001 |
| Platelet count (109/L) | 229 (196–265) | 225 (194–261) | < 0.001 |
| Alanine transaminase (U/L) | 14 (10.90–20) | 14 (10.70–19.50) | < 0.001 |
| Aspartate aminotransferase (U/L) | 16.20 (14–20) | 16.10 (14–20) | 0.282 |
| Albumin (g/L) | 42 (39.10–44.40) | 42.50 (40–44.70) | < 0.001 |
| Direct bilirubin (μmol/L) | 9.50 (7.40–12.10) | 9.80 (7.60–12.50) | < 0.001 |
| Creatinine (μmol/L) | 53 (45–63) | 53 (45–64) | < 0.001 |
| Blood urea nitrogen (mmol/L) | 2.80 (2.30–3.37) | 2.80 (2.30–3.34) | 0.237 |
| During the 24th to 28th gestational weeks | |||
| OGTT fasting glucose (mmol/L) | 5.20 (4.69–6.54) | 4.42 (4.18–4.66) | < 0.001 |
| OGTT1h glucose (mmol/L) | 9.270 (7.77–10.40) | 7.48 (6.43–8.42) | < 0.001 |
| OGTT2h glucose (mmol/L) | 7.80 (6.51–8.90) | 6.320 (5.60–7.06) | < 0.001 |
SD standard deviation, IQR inter-quartile range (25% quantile to 75% quantile), OGTT oral glucose tolerance test. Besides age expressed as mean (SD), the other continuous variables are expressed as median (IQR). Categorical data are summarized as count (percentage).
*Between patients and controls, age was compared by using the t test, and the other continuous variables were compared using the Wilcoxon–Mann–Whitney rank sum test; all categorical variables were compared using the χ2 test.