Table 4.
Ever and Recurrent Hypertensive Disorders of Pregnancy and Cardiovascular Disease
| Pregnancy History at Age 40 | N (%) | Cases/Person-years | Hazard ratio (95% CI) |
|||
|---|---|---|---|---|---|---|
| Model 1 | Model 2 | Model 3 | ||||
|
| ||||||
| Ever HDP* | 6,639 (11.6) | 180/137,586 | 1.78 (1.52, 2.10) | 1.63 (1.38, 1.92) | 1.63 (1.39, 1.92) | |
|
| ||||||
| Number of HDP pregnancies | ||||||
|
| ||||||
| 0 | 50,498 (88.4) | 824/1,084,133 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) | |
| 1 | 5,374 (9.4) | 132/111,825 | 1.61 (1.34, 1.94) | 1.48 (1.23, 1.79) | 1.48 (1.23, 1.78) | |
| 2+ | 1,265 (2.2) | 48/25,761 | 2.53 (1.89, 3.39) | 2.26 (1.68, 3.04) | 2.28 (1.70, 3.07) | |
|
| ||||||
| First Pregnancy | Second or Later Pregnancies | |||||
|
| ||||||
| Normotensive | All Normotensive | 42,397 (74.2) | 670/906,026 | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| Normotensive | No further pregnancies | 8,101 (14.2) | 154/178,107 | 1.25 (1.04, 1.49) | 1.19 (0.99, 1.42) | 1.15 (0.96, 1.39) |
| Normotensive | Any HDP | 1,336 (2.3) | 38/28,147 | 1.80 (1.30, 2.50) | 1.65 (1.19, 2.29) | 1.67 (1.20, 2.32) |
| HDP | All Normotensive | 2,979 (5.2) | 63/61,140 | 1.46 (1.13, 1.89) | 1.36 (1.05, 1.77) | 1.36 (1.05, 1.76) |
| HDP | No further pregnancies | 1,178 (2.1) | 33/24,957 | 2.01 (1.41, 2.85) | 1.76 (1.23, 2.51) | 1.71 (1.20, 2.45) |
| HDP | Any HDP | 1,146 (2.0) | 46/23,342 | 2.78 (2.06, 3.74) | 2.45 (1.81, 3.32) | 2.45 (1.81, 3.31) |
CI: confidence interval; HDP: hypertensive disorder in pregnancy. This analysis of lifetime HDP started follow-up at age 40 and was restricted to 57,137 parous women, after excluding women who developed CVD before age 40 (n=31) and those with any pregnancies after age 39 (n=3,211). The three-category exposure variable for number of HDP pregnancies was derived from a sum of the HDP pregnancies across all lifetime pregnancies: 1) 0 HDP pregnancies, 2) 1 HDP pregnancy, 3) 2+ HDP pregnancies. The six-category exposure variable classified participants based on HDP status in first pregnancy and HDP status in second or later pregnancies: 1) Normotension in all pregnancies, 2) Normotension in first pregnancy, no additional pregnancies, 3) Normotension in first pregnancy, HDP (preeclampsia or gestational hypertension) in at least one later pregnancy, 4) HDP in first pregnancy, normotension in all subsequent pregnancies, 5) HDP in first pregnancy, no additional pregnancies, and 6) HDP in first pregnancy with recurrence in at least one later pregnancy. Women free from the endpoint at age 40 and with no births after age 39 contributed person-time to the models from age 40 on.
Model 1 is adjusted for age at first birth (years), age at NHSII enrollment (years), race/ethnicity (Black, Hispanic/Latina, Asian, White [ref], other/multi-race), and parental education (<9, 9–11, 12, 13–15, ≥16 years [ref]).
Model 2 is additionally adjusted for physical activity at ages 18–22 (never, 1–3 [ref], 4–6, 7–9, 10–12 mo/yr), pre-pregnancy smoking (never [ref], past, current), pre-pregnancy BMI (<18.5, 18.5–24.9 [ref], 25–29.9, ≥30 kg/m2), pre-pregnancy alcohol consumption (none [ref], ≤1 drink/week, 2–6 drinks/week, ≥1 drink/day), pre-pregnancy Alternative Healthy Eating Index (AHEI) score (quintiles with the fifth quintile [ref] representing the healthiest diet category), pre-pregnancy oral contraceptive use (never [ref], <2, 2–<4, ≥4 years), pre-pregnancy hypercholesterolemia (no [ref], yes), and parental history of CAD and/or stroke before age 60 (CAD only for CAD model, stroke only for stroke model, CAD or stroke for CVD models; no [ref], yes).
Model 3 is additionally adjusted for final parity (1–2 [ref], 3, 4+ births).
The reference group for the ever HDP exposure is no HDP (i.e., all normotensive pregnancies). Sample size, case count, and the hazard ratio and corresponding confidence interval for this group are equal to those shown under “Number of HDP Pregnancies” for 0 HDP pregnancies.