Incidence of intracranial hemorrhage during the non-pregnancy period and pregnancy/postpartum period by AVM status
| Risk period | AVM (n=568) | Non-AVM (n=4,022,243) | Total (n=4,022,811) | |||
| Incidence per 100 000 person-years (95% CI) | Relative risk* (95% CI) | Incidence per 100 000 person-years (95% CI) | Relative risk* (95% CI) | Incidence per 100 000 person-years (95% CI) | Relative risk* (95% CI) | |
| 52 wk prior to pregnancy | 1941.9 | Reference | 2.1 | Reference | 2.4 | Reference |
| (794.4 to 3089.5) | (1.7 to 2.6) | (1.9 to 2.9) | ||||
| 52 wk of pregnancy and postpartum | 6355.4 | 3.27 | 14.4 | 6.81 | 15.3 | 6.41 |
| (4279.4 to 8431.5) | (1.67 to 6.43) | (13.3 to 15.6) | (5.42 to 8.55) | (14.1 to 16.5) | (5.17 to 7.94) | |
| 40 wk of pregnancy | 6885.1 | 3.55 | 6.1 | 2.86 | 7.0 | 2.94 |
| (4421.3 to 9348.8) | (1.78 to 7.07) | (5.2 to 6.9) | (2.21 to 3.70) | (6.1 to 8.0) | (2.31 to 3.74) | |
| 12 wk of postpartum | 4590.1 | 2.36 | 42.4 | 19.98 | 43.0 | 17.97 |
| (917.3 to 8262.9) | (0.87 to 6.39) | (38.2 to 46.5) | (15.81 to 25.27) | (38.8 to 47.2) | (14.38 to 22.45) | |
*Relative risks were estimated using conditional Poisson regressions.
AVM, arteriovenous malformations; ICH, intracranial hemorrhage.