ASN: Pregnancy Hypertension a Caution Flag for Later-Life Cardiovascular Events

SAN DIEGO, Nov. 17 -- High blood pressure during pregnancy may a warning sign for stroke or other cardiovascular events later in life, reported researchers here.

Contrary to a long-held assumption that hypertension associated with pregnancy caused little or no further trouble after childbirth, investigators at the Mayo Clinic in Rochester, Minn., found that 50% of women who have hypertension during pregnancy will develop high blood pressure by the time they are age 52.

This contrasted with about 50% of women who do not have hypertension during pregnancy becoming hypertensive after age 60, said Vesna Garovic, M.D., at the American Society of Nephrology meeting.

Dr. Garovic identified 4,782 women from participants in the Family Blood Pressure Program in which two or more siblings developed high blood pressure before age 60. She then reviewed their records, specifically scrutinizing their health during pregnancy.

In this group of women at risk for hypertension, 643 were hypertensive during their pregnancies. "In general," she said, "we believe that about 10% of women become hypertensive when they are pregnant."

In addition, they studied effects on novel risk factors in 1755 women within the Genetic Epidemiology Network of Arteriopathy (GENOA) study of the FBPP and found.

•The risk of normotensive women in the cohort having a stroke in later life was 2.7% compared with 5.2% for women who had hypertension during pregnancy. That difference was statistically significant at the P=.003 level, she said.

•The risk of coronary heart disease for the normotensive women was 5.4% compared with 6.8% for women who were hypertensive in pregnancy (P=.049).

•The risk of hypertension later in life for normotensive women was 56.9% compared with 60.6% for women who were hypertensive in pregnancy (P<.001).

•The risk of microalbuminuria among the normotensive women was 11,7% compared with 16.8% for women who were hypertensive during pregnancy (P=.003).

•The risk of arteriosclerosis later in life as measured by the ankle brachial index was 7.7% for normotensive individuals compared with 10.6% of women who were hypertensive during pregnancy (P=.02).

Women with hypertensive pregnancies, compared with those with normotensive pregnancies, had a higher BMI (P<0.0001), In addition, they had a higher urine albumin-creatinine ratio (P=0.001), while women with normotensive pregnancies had lower creatinine levels compared to those with no history of pregnancy lasting more than six months (P=0.003).

Women with hypertensive pregnancies also had higher C-reactive protein and homocysteine levels, both when BMI was added (P=0.03 and P=0.008, respectively) and removed (P<0.0001 and P=0.002, respectively) from multiple regression models.

Dr. Garovic said clinicians who care for middle-age women need to ask about their pregnancy history in order to alert their patients to the risk of cardiovascular problems later in life.

"Women should also assume that the initiative and tell their doctors about hypertension during childhood," she said.

"It is important that doctors conduct a complete history with their patients, and should ask about conditions that occurred during pregnancy," said Frank Brosius, M.D., chairman of nephrology at the University of Michigan in Ann Arbor.

"It's important to realize that something that happened 20 or 30 years before could put our patients at risk of cardiovascular problems later in life."