Women who postpone their motherhood and get their first pregnancy after 30 are vulnerable to heart attacks, according to a research.
Older women could be more vulnerable because of hardening of their arteries and their hearts' reduced capacity to handle the stress of pregnancy, said researchers at Duke Medical Centre in North Carolina.
Researchers led by Andra James studied 12 million pregnant women and found that heart attacks affected about six out of 100,000, reported the online edition of Daily Mail.
The death toll among victims was about five percent, according to the study reported in the US heart health magazine, Circulation.
Mothers-to-be who had blood transfusions in labour were found to be seven times more likely to suffer heart attacks. However, transfusions are needed by just one percent of pregnant women and are usually to save their lives.
The risk of a heart attack during pregnancy for a 40-year-old is 30 times greater than that of a 20-year-old. A 30-year-old is at seven times more at risk, the researchers said.