The sisters of women who have complicated pregnancies may find themselves at greater risk of cardiovascular disease, research suggests.
A study of more than 1.2 million women found those who suffered pregnancy conditions such as pre-eclampsia, or who give birth to a small baby, were more than twice as likely to suffer a stroke or heart failure.
And, surprisingly, their sisters are also 40 per cent more likely to have these cardiovascular problems after giving birth – and the increased risk was seen in sisters who had no pregnancy complications themselves.
Pregnancy complications and cardiovascular disease may both be determined by similar genes in women.
It means sisters who share genetic quirks could have a greater risk of both health problems.
The findings of the Swedish study also suggest it is not just pregnancy complications which can trigger cardiovascular disease at a relatively young age.
The sisters of women with pregnancy complications may find cardiovascular disease is triggered afterwards by the impact of carrying a baby on their heart and blood vessels.
Despite this, cardiovascular disease is still not common among women until later life, with only 780 women in the large study developing it after pregnancy complications, and only 151 sisters being diagnosed.
The study found that pregnancy complications and cardiovascular disease may both be determined by similar genes in women
The sisters of those who have complicated pregnancies are 40 per cent more likely to have cardiovascular problems after giving birth
But Dr Angla Mantel, who led the study from the Karolinska Institute in Sweden, said: ‘It may be important to identify these women early to offer preventive treatment for pregnancy complications as well as lifestyle counselling and follow-up for cardiovascular disease risk.’
The study looked at cardiovascular disease in women for an average of 14 years after they first gave birth to a child. Researchers studied around 165,000 women with pregnancy complications.
Almost a third of these women had a sister who had given birth without complications – and about 60,000 of these sisters were studied.
These people were compared to 992,108 unrelated women who had given birth in the same period without pregnancy complications.
The group with pregnancy complications were 2.33 times more likely to develop cardiovascular disease. And the study, in the European Heart Journal, found their sisters had a 72 per cent higher risk of developing heart failure.
Experts say some sisters may share a risk of cardiovascular disease due to factors when growing up, such as diet or exercise.
