TABLE 4.
Age‐adjusted Incidence rate ratio (IRR) and 95% confidence interval of preeclampsia in nulliparous and multiparous pregnancies among women with preexisting hypertension or gestational hypertension
| N preeclampsia/ N total | Preeclampsia (%) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nulliparous | N preeclampsia/ N total | Multiparous | ||||||||||
| % | Crude IRR | 95% CI | Adj IRR | 95% CI | % | Crude IRR | 95% CI | Adj IRR | 95% CI | |||
| None | 66 071/2 594 032 | 2.5 | ref | ref | 22 488/3 243 821 | 0.9 | ref | ref | ||||
| Preexisting hypertension | 7361/43 122 | 17.1 | 6.9 | 6.7‐7.0 | 6.2 | 6.1‐6.4 | 7277/61 231 | 11.9 | 13.1 | 12.7‐13.4 | 12.2 | 11.9‐12.5 |
| Persistent preexisting hypertension | 5394/25 777 | 20.9 | 8.4 | 8.2‐8.7 | 7.5 | 7.3‐7.7 | 5791/38 967 | 14.9 | 16.3 | 15.9‐16.8 | 15.1 | 14.6‐15.5 |
| Gestational hypertension | 9613/130 151 | 7.4 | 3.0 | 2.9‐3.0 | 2.9 | 2.8‐3.0 | 5216/134 617 | 3.9 | 4.3 | 4.1‐4.4 | 4.2 | 4.0‐4.3 |