The latest research suggests there may be a connection between pregnancy-related high blood pressure ( pre- eclampsia) and future heart disease. Pre-eclampsia is a dangerous condition in pregnancy characterized by very high blood pressure (greater than 140/90) that can potentially harm both mother and baby. Two new studies suggest that having heart disease risk factors makes a woman more likely to develop pre-eclampsia. Women who have pre-eclampsia during pregnancy are also more likely to develop heart disease later in life compared to women who have uncomplicated pregnancies. About 3-5% of women in the developed world experience pre-eclampsia during their first pregnancy. The studies were reported in the November 2 online edition of the British Medical Journal.
In the first study, data on 3494 mothers was collected from the Norwegian birth registry. Approximately 1 in every 25 of these mothers experienced pre-eclampsia during pregnancy. Women who had risk factors for heart disease before pregnancy such as high blood pressure were more likely to develop pre-eclampsia than women without these risk factors.
Women with high blood pressure before pregnancy had the highest risk of pre-eclampsia, up to 7 times that of women with normal blood pressure. Risk of pre-eclampsia also increased as pre-pregnancy levels of triglycerides and cholesterol levels increased, with the most dramatic risk seen in those with levels above the normal range. For women with cholesterol over 218 mg/dl, the risk of pre-eclampsia was twice that in women with normal cholesterol; triglycerides over 137 mg/dl also caused a woman's risk of pre-eclampsia to almost double.
The second study, led by researchers from London's Institute for Women's Health, found that after experiencing pre-eclampsia in pregnancy women have higher rates of heart and vascular disease. In an analysis of studies including over 3 million women, those who had pre-eclampsia (about 200,000) were found to be:
- 2.2 times more likely to have heart disease after 12 years
- 3.7 times more likely to have high blood pressure after 14 years
- 1.8 times more likely to have a stroke after 10 years
- 1.8 times more likely to have blood clots after 5 years
These findings from two separate studies suggest that heart disease risk factors may predispose women both to pre-eclampsia and to later cardiovascular disease.
It is not known if the heart risk later in life in women who experience pre-eclampsia is simply explained by the earlier presence of heart disease risk, or if pre-eclampsia itself somehow increases heart risk even more. In any case, these findings emphasize the importance of controlling your risk factors, especially blood pressure, even in young women. In addition to increased heart risk, women with pre-eclampsia are more likely to have pregnancy complications such as preterm birth, stillbirth, and organ damage.
See also: J, et al. Pre-eclampsia and risk of cardiovascular disease and cancer in later life: systematic review and meta-analysis. BMJ. 2007; doi:10.1136/bmj.39335.385301.