Risk factors for venous thromboembolism (VTE) during pregnancy and the postpartum period
| Maternal characteristics | Pregnancy characteristics | Delivery characteristics | |||
| Risk factor | aOR | Risk factor | aOR | Risk factor | aOR |
| Age >35 years | 1.3 | IUGR | 3.8 | Pre-term delivery | 2.42.7 |
| Parity ≥3 | 2.4 | Pre-eclampsia | 2.9–3.1 | Prolonged labour | NA |
| BMI ≥25 kg·m−2 | 1.8–2.4 | Multiple gestation | 1.7–4.2 | Instrumental delivery | NA |
| Smoker | 2.1–3.4 | Caesarean section | 1.8–3.6 | ||
| Comorbidity | 1.6–8.7 | Stillbirth | 6.4# | ||
| Varicose veins | 2.4 | MROP | 2.2 | ||
| Thrombophilia | 3.2–34.4 | PPH ≥1000 mL | 4.1 | ||
| Prior VTE | 24.8 | Infection | 4.1–6.1 | ||
| Family history of VTE | NA | Immobility | 7.7–10.8 | ||
Adjusted odds ratio (aOR) values are representative and, for clarity, confidence intervals are not included. BMI: body mass index; IUGR: intrauterine growth restriction; MROP: manual removal of placenta; PPH: postpartum haemorrhage; NA: not available. #: incident rate ratio. Reproduced and modified from [12] with permission.