Table 2.
Hazard Ratios and 95% Confidence Intervals for the Association Between Parity Categories and Cardiovascular Outcomes: The ARIC Cohort Study, 1987–2016
| Never pregnant n = 517 | No. of live births in women with prior pregnancies | ||||
|---|---|---|---|---|---|
| 0 | 1–2 | 3–4 | 5+ | ||
| n = 138 | n = 3,108 | n = 3,126 | n = 1,694 | ||
| Composite CHD and stroke | |||||
| Events/person-years | 106/11,897 | 40/2,628 | 605/69,316 | 661/69,887 | 478/35,386 |
| Model 1 | 0.95 (0.78–1.17) | 1.65 (1.20–2.28) | 1 (ref.) | 1.08 (0.97–1.20) | 1.44 (1.26–1.63) |
| Model 2 | 0.95 (0.78–1.18) | 1.50 (1.09–2.07) | 1 (ref.) | 1.11 (0.99–1.24) | 1.28 (1.13–1.46) |
| Model 3 | 0.95 (0.77–1.18) | 1.49 (1.08–2.05) | 1 (ref.) | 1.13 (1.01–1.26) | 1.32 (1.16–1.50) |
| Model 4 | — | — | 1 (ref.) | 1.09 (0.97–1.22) | 1.26 (1.10–1.44) |
| CHD | |||||
| Events/person-years | 77/12,035 | 30/2,680 | 435/70,581 | 472/70,979 | 338/36,364 |
| Model 1 | 0.98 (0.77–1.25) | 1.72 (1.18–2.49) | 1 (ref.) | 1.07 (0.94–1.22) | 1.41 (1.22–1.63) |
| Model 2 | 0.99 (0.78–1.27) | 1.66 (1.14–2.42) | 1 (ref.) | 1.12 (0.98–1.28) | 1.34 (1.16–1.57) |
| Model 3 | 0.99 (0.77–1.26) | 1.64 (1.14–2.39) | 1 (ref.) | 1.14 (1.00–1.30) | 1.39 (1.19–1.61) |
| Model 4 | — | — | 1 (ref.) | 1.09 (0.95–1.25) | 1.29 (1.10–1.52) |
| Hospitalized myocardial infarction | |||||
| Events/person-years | 47/12,308 | 15/2,828 | 269/72,103 | 278/72,555 | 234/37,137 |
| Model 1 | 0.96 (0.71–1.31) | 1.35 (0.89–2.26) | 1 (ref.) | 1.35 (0.80–2.26) | 1.58 (1.32–1.88) |
| Model 2 | 0.98 (0.72–1.34) | 1.25 (0.74–2.11) | 1 (ref.) | 1.07 (0.90–1.27) | 1.46 (1.22–1.76) |
| Model 3 | 0.97 (0.71–1.32) | 1.23 (0.73–2.08) | 1 (ref.) | 1.09 (0.92–1.29) | 1.50 (1.24–1.80) |
| Model 4 | — | — | 1 (ref.) | 1.04 (0.87–1.24) | 1.38 (1.13–1.69) |
| Heart failure | |||||
| Events/person-years | 98/11,596 | 37/2,490 | 531/67,714 | 535/67,293 | 417/33,443 |
| Model 1 | 0.99 (0.80–1.23) | 1.81 (1.29–2.52) | 1 (ref.) | 1.00 (0.89–1.13) | 1.48 (1.30–1.68) |
| Model 2 | 1.03 (0.83–1.27) | 1.49 (1.06–2.09) | 1 (ref.) | 1.04 (0.92–1.17) | 1.22 (1.06–1.17) |
| Model 3 | 1.01 (0.81–1.25) | 1.46 (1.04–2.05) | 1 (ref.) | 1.06 (0.94–1.20) | 1.25 (1.09–1.43) |
| Model 4 | — | — | 1 (ref.) | 1.03 (0.90–1.16) | 1.17 (1.01–1.36) |
| Stroke | |||||
| Events/person-years | 37/12,503 | 15/2,871 | 229/72,509 | 263/73,382 | 206/37,329 |
| Model 1 | 0.87 (0.61–1.23) | 1.56 (0.92–2.63) | 1 (ref.) | 1.12 (0.94–1.34) | 1.62 (1.34–1.96) |
| Model 2 | 0.87 (0.62–2.05) | 1.21 (0.72–2.05) | 1 (ref.) | 1.12 (0.94–1.34) | 1.22 (1.00–1.50) |
| Model 3 | 0.85 (0.60–1.21) | 1.19 (0.70–2.02) | 1 (ref.) | 1.15 (0.96–1.37) | 1.27 (1.04–1.55) |
| Model 4 | — | — | 1 (ref.) | 1.13 (0.94–1.36) | 1.25 (1.00–1.55) |
Model 1—age.
Model 2—Model 1+combined race and center, socioeconomic deprivation, health insurance, smoking status.
Model 3—Model 2+years of reproductive life, use of the oral contraceptive pill (ever), HRT use, decade of menarche.
Model 4—Model 3+age at first pregnancy and breastfeeding duration per child.