Miscarriages Linked to Heart Disease

Feb. 20, 2003 -- Women who have a history of miscarriages early in pregnancy may be at increased risk for heart disease. A new study from the U.K. is the latest to suggest a direct link between certain complications of pregnancy and cardiovascular problems that occur later in life.

Cambridge University researchers found that women who had experienced one miscarriage prior to the birth of their first child had about a 50% increased risk of developing heart disease. Those with three or more pregnancy losses were almost two-and-a-half times the risk of women who had never miscarried. The study appears in the latest issue of the British Medical Journal.

In earlier work, lead researcher Gordon Smith, MD, PhD, and colleagues reported a strong association between complications of late pregnancy and subsequent risk of heart disease. They found that having a low birth weight baby, giving birth preterm, and giving birth with a diagnosis of preeclampsia were each associated with a doubled risk of developing heart disease within the next 15 to 20 years. Women with all three conditions had a sevenfold increase in risk.

"We hypothesized that the same association might be seen in women who have early pregnancy losses," Smith tells WebMD. "We aren't suggesting that they already have heart damage and that is why the pregnancies go wrong. Rather, we believe the same factors that give rise to pregnancy complications are also promoting the development of heart disease."

In their latest study, the research team analyzed national data on births in Scotland between 1981 and 1985, as well as deaths and hospital admissions due to ischemic heart disease between 1981 and 1999. After adjusting for other known heart disease risk factors, such as high blood pressure and the mother's age, the researchers found that women with three or more early pregnancy losses were more than twice as likely to develop heart disease as women who had never had a miscarriage.

Smith tells WebMD that a group of blood clotting conditions called thrombophilias, which is believed to play a part in many miscarriages, could explain the link between pregnancy complications and heart disease. Thrombophilias may be inherited or acquired and are thought to interfere with embryo implantation and the development of the placenta.

He says women with a history of unexplained pregnancy losses should be evaluated for the presence of certain antibodies seen with acquired thrombophilias. Those who have the antibodies might be candidates for risk-lowering interventions, such as taking a daily low-dose aspirin.

Endocrinologist Naveed Sattar, MD, says women who have had pregnancy complications should be especially vigilant about being screened for heart disease later in life and adopting healthy lifestyles to lower their risk. An associate professor at Scotland's Glasgow Royal Infirmary University, Sattar published his own study last year linking pregnancy complications with heart disease risk. Two studies reviewed by Sattar suggested that women who gave birth to low birth weight babies were seven to 11 times more likely to die from heart problems as women who gave birth to babies of normal weight.

"We need much bigger studies to confirm all of these findings," he tells WebMD. "One thing we can do is bring women who have had these complications back when they reach their 40s and 50s and look for the early signs of heart disease."

The authors say a woman's reproductive history may be informative of future heart disease.