Table 2.
Maternal characteristics according to different maternal serum 3-epi-25(OH)D3 level at the mid-gestation of pregnancy
| Maternal serum 3-epi-25(OH)D3 (nmol/L) | ||||||
|---|---|---|---|---|---|---|
| ≤1.00 | 1.01-1.50 | 1.51-2.00 | 2.01-3.00 | > 3.00 | P | |
| (n = 275) | (n = 281) | (n = 261) | (n = 409) | (n = 276) | ||
| Maternal age, y | 30.0 ± 4.8 | 30.7 ± 4.8 | 30.9 ± 5.0 | 30.9 ± 4.7 | 31.5 ± 4.8 | 0.01 |
| Primigravida | 188 (68.4) | 175 (62.3) | 166 (63.6) | 249 (60.9) | 155 (56.2) | 0.06 |
| Prepregnancy BMI, kg/m2 | 20.9 ± 3.3 | 20.5 ± 2.5 | 20.6 ± 2.7 | 20.6 ± 2.8 | 20.6 ± 2.7 | 0.68 |
| BMI at blood sampling, kg/m2 | 24.9 ± 3.5 | 24.3 ± 2.9 | 24.2 ± 2.8 | 24.3 ± 2.8 | 24.3 ± 2.8 | 0.08 |
| Maternal pre-pregnant weight, kg | 52.4 ± 9.0 | 51.9 ± 7.0 | 52.0 ± 7.9 | 51.6 ± 7.3 | 51.3 ± 7.3 | 0.50 |
| Maternal weight at blood sampling, kg | 62.5 ± 9.7 | 61.5 ± 8.1 | 61.1 ± 8.5 | 60.8 ± 7.7 | 60.6 ± 7.5 | 0.054 |
| Smoker | 7 (2.5) | 7 (2.5) | 5 (1.9) | 5 (1.2) | 10 (3.6) | 0.33 |
| Alcohol drinker | 2 (0.7) | 0 | 0 | 0 | 1 (0.4) | 0.19 |
| Maternal glycemic status, AUCglu | 752.6 ± 121.5 | 769.8 ± 121.9 | 789.3 ± 140.5 | 794.2 ± 132.5 | 804.8 ± 138.0 | <0.001 |
| Gestation age at blood sampling, wk | 27.8 ± 1.3 | 27.7 ± 1.2 | 27.7 ± 1.3 | 27.7 ± 1.4 | 27.7 ± 1.3 | 0.90 |
| Baby’s gender (male) | 121 (44.0) | 147 (52.3) | 130 (49.8) | 210 (51.3) | 164 (59.4) | 0.01 |
| Ambient solar radiation, MJ/m2 | 352.0 ± 73.0 | 371.7 ± 80.5 | 389.0 ± 69.2 | 407.2 ± 73.1 | 423.4 ± 74.5 | <0.001 |
| Maternal 25(OH)D3 level, nmol/L | 37.1 ± 14.0 | 45.7 ± 12.4 | 52.4 ± 11.8 | 62.8 ± 14.3 | 75.4 ± 17.7 | <0.001 |
Continuous and categorical variables were expressed as mean ± SD and n (proportion in %), and were compared by ANOVA and χ 2 tests, respectively.
Abbreviations: 3-epi-25(OH)D3, isomeric form of 25(OH)D3; AUCglu, area under the curve of maternal glucose levels at the oral glucose tolerance test during pregnancy; BMI, body mass index.