Death rates from ischemic heart disease in women with a history of hypertension in pregnancy

BACKGROUND: Evidence about the influence of hypertension in pregnancy on later health and in particular the risk of cardiovascular disorders is conflicting, although a link has been suggested. In a population-based study with a long follow-up time the potential association between hypertension in pregnancy, preeclampsia and eclampsia with increased death rates from ischemic heart disease (IHD) was investigated. METHODS: All 7543 case records at the main maternity hospital in Iceland during 1931-1947 were reviewed to identify women with hypertension in pregnancy, subdivided by parity and severity of disease into those with eclampsia, preeclampsia and hypertension alone. Information on those who had died was obtained from death certificates, supplemented by autopsy reports and hospital records. Death rates from IHD were compared to population data from public health and census reports during corresponding periods and between study groups. RESULTS: Of 374 hypertensive women 177 had died. The death rate was slightly higher among women with any hypertension in pregnancy than in the reference population (RR = 1.20; 95% CI 1.01-1.42). About half of the increase was attributed to excess mortality from IHD with a relative risk of dying of 1.47 (95% CI 1.05-2.02). The relative risk of dying from IHD was significantly higher among eclamptic women (RR = 2.61; 95% CI 1.11-6.12) and those with preeclampsia (RR = 1.90; 95% CI 1.02-3.52) than those with hypertension alone. Parous women at the index pregnancy had a twofold higher risk of dying from IHD than primigravid women (RR = 2.05; 95% CI 1.19-3.55; p = 0.01). CONCLUSION: There is an indication of increased death rates among women with a history of hypertension in pregnancy, where ischemic heart disease may be more common than in the general population.