Baseline characteristics
| N | Overall | CHD | VHD |
| 2742 | 1599 | 862 | |
| Age, years (SD) | 29.2 (±5.5) | 28.9 (±5.3) | 29.5 (±5.9) |
| BMI, kg/m2 (SD) | 25.3 (±4.8) | 24.3 (±4.5) | 26.2 (±4.7) |
| Nulliparous, % | 45.4 | 52.8 | 31.8 |
| Singleton pregnancy, % | 97.9 | 98.5 | 96.8 |
| Systemic ventricle dysfunction, % | 6.5 | 5.5 | 2.7 |
| Hypoxia, % | 4.0 | 6.5 | 1.4 |
| Atrial fibrillation, % | 2.4 | 0.4 | 6.5 |
| Hypertension, % | 6.0 | 5.9 | 4.1 |
| Diabetes mellitus, % | 1.4 | 1.4 | 1.4 |
| Signs of heart failure before pregnancy, % | 9.3 | 5.6 | 15.7 |
| NYHA III or IV, % | 2.7 | 1.3 | 4.6 |
| Current smoking, % | 4.1 | 4.6 | 2.4 |
| Prior cardiac intervention, % | 56.5 | 69.4 | 43.9 |
| Anticoagulants in therapeutic dosage, % | 12.4 | 4.8 | 28.1 |
| Emerging country, % | 33.4 | 20.1 | 58.2 |
BMI, body mass index; CHD,congenital heart disease; NYHA, New York Heart Association.