Pre-existing risk factors | Score |
Previous VTE (except a single event related to major surgery) | 4 |
Previous VTE provoked by major surgery | 3 |
Known high-risk thrombophilia | 3 |
Medical comorbidities cancer, heart failure; active systemic lupus erythematosus, inflammatory polyarthropathy or inflammatory bowel disease; nephrotic syndrome; type I diabetes mellitus with nephropathy; sickle cell disease; current intravenous drug user | 3 |
Family history of unprovoked or oestrogen-related VTE in first-degree relative | 1 |
Known low-risk thrombophilia (no VTE) | 1 |
Age (> 35 years) | 1 |
Obesity (BMI > 30/>40) | 1/2 |
Parity ≥ 3 | 1 |
Smoker | 1 |
Gross varicose veins | 1 |
Obstetric risk factors | |
Pre-eclampsia in current pregnancy | 1 |
ART/IVF (antenatal only) | 1 |
Multiple pregnancy | 1 |
Caesarean section in labour | 2 |
Elective caesarean section | 2 |
Mid-cavity or rotational operative delivery | 1 |
Prolonged labour (>24 hours) | 1 |
PPH (>1 L or transfusion) | 1 |
Preterm birth < 37 + 0 weeks in current pregnancy | 1 |
Stillbirth in current pregnancy | 1 |
Transient risk factors | |
Any surgical procedure in pregnancy or puerperium except immediate repair of the perineum | 3 |
Hyperemesis | 3 |
Ovarian Hyperstimulation Syndrome (first trimester only) | 4 |
Current systemic infection | 1 |
Immobility, dehydration | 1 |