Table 2.
Hazard ratios for dementia overall and by timing of onset, according to history of pregnancy loss, in a cohort of women with ≥1 live births, stillbirths, or miscarriages in Denmark in the period 1977–2015
| History of pregnancy loss | Dementia overall |
Dementia with onset <65 years |
Dementia with onset ≥65 years |
||||||
|---|---|---|---|---|---|---|---|---|---|
| Person-years (× 103) | No. of events | HR∗ (95% CI) | Person-years (× 103) | No. of events | HR∗ (95% CI) | Person-years (× 103) | No. of events | HR∗ (95% CI) | |
| Stillbirth | 180 | 28 | 1.86 (1.28–2.71) | 177 | 18 | 1.70 (1.06–2.72) | 3 | 10 | 2.25 (1.20–4.22) |
| ≥2 miscarriages | 764 | 74 | 1.06 (0.84–1.35)† | 751 | 61 | 1.25 (0.97–1.63) | 13 | 13 | 0.61 (0.34–1.08) |
| 1 miscarriage | 3462 | 402 | 0.99 (0.87–1.12) | 3365 | 215 | 0.99 (0.79–1.13) | 10 | 187 | 0.98 (0.78–1.24) |
| No pregnancy loss | 17,266 | 1684 | 1 (Ref) | 16,817 | 1109 | 1 (Ref) | 449 | 575 | 1 (Ref) |
Abbreviations: CI, confidence interval; HR, hazard ratio.
∗
Hazard ratios are adjusted for birth year (5-year intervals), parity (1, 2, ≥3), and age (the underlying time scale in the Cox model).
†
For 2 miscarriages, the HR was 1.05 (95% CI 0.81–1.37); for ≥ 3 miscarriages, the HR was 1.10 (95% CI 0.66–1.84).