Women who experience miscarriages or pregnancy loss and do not have children are at greater risk of cardiovascular problems such as heart disease and stroke, compared with women who have only one or two children, says a new study.
It could be because repeated pregnancies could result in long-lasting changes within the body including weight gain, especially around the waist, and increased levels of cholesterol in the blood.
"Conditions such as heart disease and stroke together are the leading cause of death in women in the developed world and it is essential that we understand why this is the case," said Clare Oliver-Williams, a research student from the University of Cambridge.
"There is a relation between cardiovascular disease risk and both pregnancy loss and having a large number of births," Oliver-Williams added.
The study, published in the Journal of Women's Health, also found that women with five or more births had a 38 per cent higher risk of having serious heart attack, regardless of how long they breastfed.
Since the number of children a woman has also encompasses other factors including child-rearing, age at menopause and health conditions, the researchers say it is unclear whether the increased risk of heart failure, coronary heart disease and heart attacks reflect the direct impact of repeated pregnancies, or the stressors associated with rearing multiple children, or both.
During pregnancy, the mother's body experiences changes including weight gain, accumulation of abdominal fat, higher levels of cholesterol, increased insulin resistance, and changes in the structure of the heart.
Although such changes are temporary, they are known to be the risk factors for cardiovascular disease in the general population, the researchers noted.
For the study, the team analysed data from more than 8,500 women, aged 45-64 years.
Lifestyle changes, such as exercise and diet can help reduce the risk of cardiovascular disease.