Table 3. Rate of VTE per 100,000 person-years using different definitions of VTE in and around pregnancy (for pregnancies resulting in live or stillbirths).
| Time period | VTE definition A1, B2 or C3 | VTE definition A1 or B2 | VTE definition A1 | |||
| n | Rate* (95%CI) | n | Rate* (95%CI) | n | Rate* (95%CI) | |
| Not pregnant | 2,817 | 61 (58–63) | 2040 | 44 (42–46) | 1480 | 32 (30–33) |
| Antepartum | 377 | 240 (217–266) | 268 | 171 (151–192) | 156 | 99 (85–116) |
| Trimester 1 | 47 | 95 (71–127) | 41 | 83 (61–113) | 23 | 46 (31–70) |
| Trimester 2 | 76 | 148 (118–186) | 49 | 95 (74–126) | 30 | 58 (41–83) |
| Trimester 3 | 254 | 450 (398–509) | 178 | 315 (272–365) | 103 | 182 (150–221) |
| Around delivery | 76 | 3192 (423–546) | 38 | 1596 (1161–2193) | 34 | 1428 (1020–1998) |
| Postpartum | 237 | 481 (423–546) | 187 | 379 (329–438) | 135 | 274 (231–324) |
| Early postpartum | 200 | 801 (695–920) | 157 | 629 (537–735) | 177 | 468 (391–561) |
| Late postpartum | 37 | 151 (109–208) | 30 | 122 (95–175) | 18 | 73 (46–116) |
*
Rate per 100,000 person-years.
**
With women recorded as having a VTE event if they had a diagnosis in either database.
1
Recorded VTE with supporting anticoagulant prescription, or medical code indicating anticoagulant therapy within 90 days of the event or death within 30 days of the event.
2
Recorded VTE codes with supporting sign or symptom of VTE within 15 days before or after the date of event.
3
Recorded VTE with no evidence of signs and symptoms or anticoagulant therapy.