Association between gestational hypertension and risk of cardiovascular disease among 617 589 Norwegian women

Abstract

Background--Preeclampsia and gestational hypertension (GH) are the most common hypertensive pregnancy disorders. Preeclampsia has been linked to increased risk of cardiovascular disease (CVD), but a similar association for GH has not been established. We aimed to determine the association between GH and subsequent CVD, and explore the additional role of small-forgestational- age infants, preterm delivery, and parity. Methods and Results--Data from the Medical Birth Registry of Norway were linked to the Cardiovascular Disease in Norway project and the Norwegian Cause of Death Registry. Hazard ratios and 95% confidence intervals were computed using Cox proportional hazard regression, comparing women with and without GH during their first and/or second pregnancy. We included all women with a first delivery from 1980 through 2009 (n=617 589) and followed them for a median of 14.3 (quartile 1-quartile 3: 6.9-21.5) years. Women with GH in the first pregnancy had 1.8-fold (95% confidence interval, 1.7-2.0) higher risk of subsequent CVD compared with women without any hypertensive pregnancy disorder. When GH occurred in combination with small-forgestational- age infants and/or preterm delivery, the hazard ratio was 2.6 (95% confidence interval, 2.3-3.0). When women with GH were compared with women with preeclampsia, the risk of CVD was comparable when the pregnancy complications occurred in either the first or second pregnancy but was significantly higher for preeclampsia without complications when the disorder occurred in both pregnancies. Conclusions--GH was associated with increased risk of subsequent CVD, and the highest risk was observed when GH was combined with small-for-gestational-age infants and/or preterm delivery.