Women who develop high blood pressure (hypertension) during pregnancy have elevated rates of cardiovascular disease (CVD) and kidney disease later in life, reports a paper being presented at the American Society of Nephrology's 39th Annual Meeting and Scientific Exposition in San Diego.
'Along with menopause and hormone use, hypertensive pregnancy diseases may contribute to gender-specific differences in the clinical course and outcomes of CVD,' comments Dr. Vesna D. Garovic of the Mayo Clinic in Rochester, Minnesota, lead author of the new study. 'Improved screening, prevention, and treatment strategies may not only optimize management of problems related to high blood pressure during pregnancy, but also have a long-term impact on women's cardiovascular events and outcomes years after the affected pregnancies.'
Dr. Garovic and her colleagues analyzed data on 4,782 women with a high family risk of hypertension from the study of the National Heart, Lung and Blood Institute Family Blood Pressure Program. Six hundred forty-three women had problems with high blood pressure during a previous pregnancy. Rates of CVD events—such as myocardial infarction (heart attack) and stroke—were compared to those of women who had pregnancies without hypertension (normotensive) or who had never had a pregnancy lasting longer than 6 months.
Women who had hypertension during pregnancy had significantly higher rates of various types of CVD events after age 40. The risk of stroke was twice as high as in women with normotensive pregnancies, while the risk of coronary heart disease events (such as myocardial infarction) was 1.5 times higher. Women with hypertensive pregnancies were also 1.5 times more likely to develop high blood pressure after age 40.
Hypertension during pregnancy was also associated with an increased risk of microalbuminuria—small amounts of the protein albumin in the urine, an early sign of kidney disease. In addition, the study suggested that women with hypertensive pregnancies also had higher levels of some recently recognized CVD risk factors, including C-reactive protein and homocysteine. Hypertension affects ten percent of pregnancies in the United States and remains a leading cause of health problems and death for both mother and baby. 'Traditionally, these hypertensive pregnancy disorders-including a potentially serious complication called pre-eclampsia—have not been considered to have any long-term impact on the mother's health,' says Dr. Garovic. 'However, our results support the role of hypertension during pregnancy as a risk factor for CVD later in life.'
What might explain the link between hypertensive pregnancy disorders and the development of CVD later in life? 'It may be that these disorders, especially pre-eclampsia, share common risk factors with CVD, such as obesity, diabetes, and kidney disease,' replies Dr. Garovic. 'Or, it may be that hypertension in pregnancy induces long-term metabolic and vascular abnormalities, which may lead to an increase in overall CVD risk later in life.'
High blood pressure during pregnancy is an under-recognized risk factor for CVD, the researchers believe. 'When assessing a woman's overall risk profile for CVD, doctors should screen for hypertensive disorders of pregnancy,' concludes Dr. Garovic. 'We suggest that women with hypertensive pregnancies be monitored closely for asymptomatic cardiovascular events and treated aggressively for modifiable risk factors.'