| General | Activation of Virchow’s triad, venous stasis from obstruction to flow, hypercoagulability, endothelial damage |
| Inherited thrombophilia, previous venous thromboembolism | |
| Antepartum | Multiple births |
| Varicose veins | |
| Inflammatory bowel disease | |
| Urinary tract infection | |
| Diabetes | |
| Hospitalization for non-delivery reasons (particularly those >3 days) | |
| BMI ≥30 kg/m2 | |
| Increased maternal age ≥35 years | |
| Postpartum | Cesarean section |
| Medical comorbidities (eg, varicose veins, cardiac disease, inflammatory bowel disease) | |
| BMI ≥25 kg/m2 | |
| Young gestational age (preterm delivery <36 weeks) | |
| Obstetric hemorrhage | |
| Stillbirth | |
| Increased maternal age ≥35 years | |
| Hypertension | |
| Smoking | |
| Eclampsia or preeclampsia | |
| Postpartum infection |
