Previous studies have shown that women usually show changes in vascular properties blood volume and heart rates during pregnancy. However the impact of pregnancy on subsequent heart disease has been debated. In the new study a team from the Huazhong University of Science and Technology in China reviewed 10 studies. It involved nearly three million women worldwide with more than 150000 diagnosed with heart disease or strokes during the following six to 52 years. The findings published in the European Society of Cardiology journal showed that giving birth has a 14 per cent higher risk of heart disease and strokes.