Table 3.
Rate of venous thromboembolism (VTE) by admission to hospital and after hospital stay
| Variable | No of VTE | Rate* (95% CI) | IRR (95% CI) | |
|---|---|---|---|---|
| Adjusted 1† | Adjusted 2‡ | |||
| Antepartum overall | ||||
| Time outside hospital | 150 | 97 (83 to 114) | 1.00 | 1.00 |
| Hospital admission | 6 | 1752 (787 to 3900) | 18.2 (8.04 to 41.3) | 17.5 (7.69 to 40.0) |
| After discharge | 20 | 676 (436 to 1048) | 7.08 (4.41 to 11.3) | 6.27 (3.74 to 10.5) |
| Pregnancies not complicated by BMI >30 or major medical comorbidity§ | ||||
| Time outside hospital | 109 | 84 (69 to 101) | 1.00 | — |
| Hospital admission | 5 | 1821 (757 to 4375) | 22.0 (8.97 to 54.3) | — |
| After discharge | 15 | 623 (375 to 1034) | 7.56 (4.36 to 13.1) | — |
| Variation by duration of hospital stay (combining admission/after discharge) | ||||
| Antepartum overall: | ||||
| Time outside hospital | 150 | 97 (83 to 114) | 1.00 | 1.00 |
| <3 days | 13 | 558 (331 to 943) | 5.85 (3.37 to 10.1) | 4.05 (2.23 to 7.38) |
| ≥3 days | 13 | 1511 (858 to 2661) | 15.7 (8.71 to 28.5) | 12.2 (6.65 to 22.7) |
| Time outside pregnancy | ||||
| Time outside hospital | 326 | 28 (25 to 31) | 1.00 | — |
| Hospital admission | 11 | 1890 (1046 to 3412) | 66.2 (36.3 to 120) | — |
| After discharge | 35 | 911 (654 to 1269) | 32.3 (22.8 to 45.8) | — |
IRR=incidence rate ratio.
*Rate calculated per 100 000 person years.
†Adjusted for maternal age and calendar year when not stratified by them.
‡Adjusted for maternal age, calendaryear, BMI, gestational infection, cardiac disease, varicose vein, gestational diabetes, and hyperemesis.
§Including varicose vein and cardiac disease.