Women who experience complications during pregnancy, particularly more than one, may have an increased risk of dying from heart disease later in life, a new study has found.

Heart disease is the biggest killer of women in Ireland.

US researchers looked at over 15,500 pregnant women who had been enrolled in a health study between 1959 and 1967. By 2011, when the average age of the women was 66, 368 had died as a result of heart disease.

An analysis of the women's health data found that pre-eclampsia during early pregnancy was strongly linked to premature death as a result of heart disease before the age of 60.

However, they also found that a combination of certain complications raised the risk for women as well. Women who had pre-existing high blood pressure that was diagnosed up to 20 weeks of pregnancy, and delivered their baby prematurely, were over seven times more likely to die from heart disease later in life than those with uncomplicated pregnancies.

Those who had pre-existing high blood pressure and pre-eclampsia, which is characterised by high blood pressure and high levels of protein in the urine, were 5.6 times more likely to die from heart disease.

Those with high blood pressure during pregnancy who gave birth prematurely were five times more likely to die from heart disease, while those who had pre-existing high blood pressure and had a smaller than average baby were 4.8 times more likely to die from heart disease.

The study also identified two new pregnancy complications that increase the risk of heart disease death. Those with glycosuria - high levels of sugar in the urine - were 4.2 times more likely to die, while those with haemoglobin decline - a measure of red blood cells' ability to carry oxygen through the body - were 1.7 times more likely to die from heart disease later in life.

"Pregnancy is really a stress test for the cardiovascular system. These risk factors, which are in the patient's health record, should lead doctors to discuss with these women ways to reduce their risk of heart attack and other cardiovascular diseases," suggested the researchers.

They emphsised that huge progress has been made in the field of heart medicine and these complications should act as ‘early warning signs that tell you to pay attention to risk factors that you can control'.

Details of these findings are published in the journal, Circulation.

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