Women who've suffered repeated miscarriages may later face an increased risk of heart attack, according to a new study.
Miscarriage occurs in up to one in five pregnancies.
The findings are based on more than 11,500 women who took part in a large European study tracking the impact of diet and lifestyle on disease.
All of the women had been pregnant at least once, and the researchers collected further data on those whose pregnancies had ended prematurely, either as a result of miscarriage or abortion, or whose babies had been stillborn.
Among the entire group, almost one in four (25 percent) had suffered at least one miscarriage, and almost one in five (18 percent) had had at least one abortion. Additionally, 2 percent had experienced a stillbirth.
Of the 2,876 women who had miscarried, 69 had it happen more than three times. These women, the study found, tended to weigh more. Those who had experienced a stillbirth were less physically active and had higher rates of diabetes and high blood pressure, all of which are independent risk factors for heart attack and stroke.
Over a period of about 10 years, 82 women had a heart attack and 112 had a stroke.
The researchers found no significant association between any of the types of pregnancy loss and an increased risk of stroke. But strong patterns emerged for stillbirth and miscarriage.
Each miscarriage a woman had suffered was found to be associated with a 40 percent increased risk of a heart attack, and those women who miscarried more than twice were more than four times as likely to have a heart attack.
Having experienced at least one stillbirth increased by 3.5 times the women's risk of a heart attack.
“These results suggest that women who experienced spontaneous pregnancy loss are at a substantially higher risk of [heart attack] later in life,” wrote the authors.
“Recurrent miscarriage and stillbirth are strong gender predictors for [this], and thus should be considered as important indicators for monitoring cardiovascular risk factors and preventive measures,” they added.
The researchers noted several of the conditions that predispose a woman to have a miscarriage — including diabetes and elevated levels of the protein homocysteine — also put people at risk for heart disease.
And miscarriage can sometimes lead to infections, which are also liked with cardiovascular disease, they said.
The study is published online on Dec. 1 in the journal Heart.