Women who have experienced pregnancy complications have an increased risk of cardiovascular disease. Now, a new study from Karolinska Institutet published in the European Heart Journal shows that sisters of women with complicated pregnancies are also at higher risk, even if they had uncomplicated pregnancies. The findings suggest that genes and shared environmental factors may influence the association between pregnancy complications and cardiovascular disease risk.

It is well known that complications during pregnancy, such as high blood pressure and premature labour, increase the risk of cardiovascular disease later in life. However, it is unknown whether this association can be explained by familial factors. Researchers have investigated this through a registry study of Swedish women who gave birth to their first child between 1992 and 2019.

The researchers identified women who had experienced pregnancy complications and their sisters who had given birth during the same period but had not experienced a pregnancy complication. They compared the risk of developing cardiovascular disease for the women with complicated pregnancies, their sisters with uncomplicated pregnancies and an unrelated control group.

The study showed that the sisters also had an almost 40 percent higher risk of cardiovascular disease compared to the women in the control group.

“Our results show that the risk of cardiovascular disease after a pregnancy complication does not depend solely on the pregnancy itself, but can be influenced by genes and environmental factors,” says lead author Ängla Mantel, docent at the Department of Medicine, Solna, Karolinska Institutet.

The findings suggest that women with pregnancy complications, and their sisters, may benefit from cardiovascular disease prevention interventions.

“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,” says Ängla Mantel.

The study was funded by SFOepi at Karolinska Institutet and the Swedish Heart-Lung Foundation. There are no reported conflicts of interest.