Hypertension in pregnancy and long-term cardiovascular mortality: A retrospective cohort study

Background There is growing evidence that hypertensive disorders of pregnancy are associated with increased long-term cardiovascular mortality in the mother. Hypertension in pregnancy, until recently, however, has been ignored largely as a risk factor for future cardiovascular disease and mortality because the link between the 2 is not fully understood. Objective To determine the association between women with hypertension in pregnancy and long-term cardiovascular disease mortality. Study Design All women who delivered at a metropolitan hospital between the periods of January 1, 1980, and December 31, 1989, were identified by use of the International Statistical Classification of Diseases and Related Health ProbleMS 9th Revision, Australian Modification. Results The total number of deliveries in the given time period was 31,656, with 4387 (14%) of the women identified as having had hypertension in their pregnancy. Using information from the New South Wales Births, Deaths and Marriages Registry and the Australian Bureau of Statistics Death Registry, we identified a total of 651 deaths from this cohort (n = 31,656). There were 521 deaths among the women who remained normotensive in their pregnancy and 129 deaths for women who had hypertension during their pregnancy. Overall, the women with hypertensive disorders of pregnancy were at greater risk of death than the women who remained normotensive in their pregnancy (odds ratio 1.56; 95% confidence interval 1.28-1.89; P <.001). Conclusion Women with a history of hypertension in their pregnancy are at an increased risk of future cardiovascular mortality, and this work identifies a group of women who may benefit from early screening and intervention strategies to help decrease their risk of future cardiovascular disease.