An aneurysm happens when part of a blood vessel (artery)  swells either because it is injured, or if the wall of the blood vessel is weak. Aneurysms can happen in the aorta (aortic aneurysms), the brain (brain or cerebral aneurysms), or peripherally in other body parts (peripheral aneurysms).  

Aortic aneurysms are located in the aorta, the blood vessel that comes out of the heart and supplies the remaing body with arterial blood. The aorta runs through the chest and the abdomen, therefore  here are two types of aortic aneurysm:

1. Thoracic aortic aneurysm - these occur in the part of the aorta running through the chest
2. Abdominal aortic aneurysm - these occur in the part of the aorta running through the abdomen

Rupture of aortic aneurysms is rare but life-threatening and potentially lethal emergency whose risk factors in pregnancy were recently reviewed. A recent review discussed management of aneurysms during pregnancy. During pregnancy there are many changes in the body potentially increasing the strain inside the blood vessels including the aorta. In addition, pregnancy hormones can have an effect on blood vessels. There are certain diseases which increase the risks to the aorta rupturing such as Marfan syndrome, Ehlers-Danlo syndrome, or other aortic abnormalities.

All women with known aortic disease should be extensively counselled before pregnancy and the risks to the aorta rpturing shoudl be assessed and discussed including risk of disease and death. The size of the aorta should be measured before conception, becausde an increase in size before and during pregnancy, is essential to try and estimate the risk of aortic dissection.

Depending on the size of the aneurysm, repairing the aneurysm and a dilated aorta prior to pregnancy may improve pregnancy outcome.