Table 1.
Baseline characteristics of the study population.
| Case (N = 474) | Control (N = 948) | p 1 | |
|---|---|---|---|
| Sociodemographic characteristics, % | |||
| Maternal age < 30 years | 66.5 | 65.8 | 0.812 |
| Maternal work, in employment | 50.6 | 78.7 | <0.001 |
| Maternal education, senior high school or above | 58.9 | 80.7 | <0.001 |
| Urban residence | 66.0 | 71.6 | 0.030 |
| Nulliparity | 57.8 | 80.3 | <0.001 |
| Maternal health-related factors in early pregnancy, % | |||
| Passive smoking | 33.5 | 9.3 | <0.001 |
| Anemia | 16.9 | 10.9 | 0.001 |
| Medication use | 41.6 | 30.4 | <0.001 |
| Folate/iron supplements use | 76.6 | 89.2 | <0.001 |
| Birth weight < 2500 g, % | 9.7 | 5.3 | 0.003 |
| Gestational age < 37 weeks, % | 6.1 | 5.1 | 0.407 |
| Daily nutrients intakes during pregnancy, median (25th percentile, 75th percentile) | |||
| Total energy, kcal | 1753.2 (1452.4, 2086.1) | 1907.1 (1563.3, 2415.9) | <0.001 |
| Protein, g | 44.5 (32.0, 60.5) | 56.9 (40.9, 78.9) | <0.001 |
| Fat, g | 30.9 (19.0, 47.8) | 41.7 (29.0, 59.5) | <0.001 |
| Monounsaturated fatty acid, g | 6.9 (3.9, 12.2) | 9.7 (6.6, 14.4) | <0.001 |
| Saturated fatty acid, g | 13.1 (8.1, 19.3) | 17.4 (12.6, 25.0) | <0.001 |
| Carbohydrate, g | 185.6 (142.0, 237.7) | 190.9 (142.5, 269.8) | 0.057 |
| Iron, mg | 17.5 (12.6, 23.3) | 20.4 (14.3, 28.9) | <0.001 |
| Zinc, mg | 4.7 (3.1, 6.8) | 6.4 (4.6, 9.1) | <0.001 |
| Selenium, μg | 22.7 (15.0, 32.5) | 30.8 (21.9, 43.7) | <0.001 |
| Calcium, mg | 457.4 (315.8, 643.8) | 500.9 (359.8, 707.0) | <0.001 |
| Niacin, mg | 9.6 (7.3, 13.2) | 12.5 (9.0, 17.3) | <0.001 |
| Folate, μg | 195.1 (161.3, 242.9) | 220.2 (181.5, 270.5) | <0.001 |
| Vitamin C, mg | 63.5 (42.1, 107.0) | 77.0 (51.8, 123.2) | <0.001 |
| Dietary quality scores, median (25th percentile, 75th percentile) | |||
| GDQS | 27.5 (23.7, 31.0) | 31.0 (27.3, 34.3) | <0.001 |
| MDS | 4.0 (2.0, 5.0) | 5.0 (3.0, 6.0) | <0.001 |
GDQS, Global Diet Quality Score; MDS, Mediterranean Diet Score; 1 Categorical variables are compared between groups by the χ2 test, and continuous variables are compared between groups by the Mann–Whitney U test.