Miscarriage tied to family heart disease history

New findings suggest there could be a link between parents' heart disease and their grown-up daughter's risk of having miscarriages.

Researchers in the UK found that women who miscarried twice before having their first child had a higher than average risk of having parents with heart disease. This risk was even higher in women who'd miscarried three times before giving birth, said Dr. Gordon Smith of Cambridge University and his colleagues.


For the moment, Smith told Reuters Health, this news can't be used to help a woman lower her risk of multiple miscarriages. What it can do, he said, is serve as a clue for researchers studying how genes passed from parent to child affect both problems: heart disease and miscarriage.

In a previous study of nearly 130,000 Scottish women, Smith and his team had shown that those with frequent miscarriages were more likely to have heart problems as they grew older (see Reuters Health story of February 21, 2003). This made the researchers wonder whether such women -- already at risk for developing heart disease themselves -- were also more likely to have a family history of heart disease, which would suggest the two were genetically related.

So the researchers looked at data on nearly 75,000 women who delivered a first child between 1992 and 2006, along with medical information on the mothers and fathers of roughly two-thirds of the women.

Compared to women who gave birth without any previous miscarriages, women who had two miscarriages were 25 percent more likely to have parents who died or were hospitalized due to heart disease. When a woman had three miscarriages before giving birth, she was 56 percent more likely to have parents with serious heart disease.

Factors like income and education and whether the woman smoked at the time of her first birth didn't explain the link between heart disease in parents and miscarriages in their grown daughters.

In early pregnancy, Smith said, the heart and blood vessels must do a great deal to ensure that the pregnancy continues, for example linking the fetus to the maternal blood supply. Some sort of hidden heart issues, he added, could definitely affect this process.

Of course, having parents with heart disease doesn't mean a woman will have multiple miscarriages -- and in fact, the majority of such women won't miscarry even once. The reverse is also true: having a daughter who miscarries doesn't mean the parents are going to develop heart conditions.

But if future research does prove there's a link for some women, "if we can identify the gene or genes involved we can potentially identify the mechanism and therefore potentially identify the treatment," Smith said.