The information provided below is for readers based in the United States of America. Readers outside of the United States of America should seek the information from local sources.

What is an aneurysm during pregnancy?

An aneurysm is a bulge, ballooning, or other distention in a blood vessel due to a weakened vessel wall being stretched over time by the pressure of the blood. Although aneurysms can occur both in arteries and veins, venous aneurysms are very rare, while arterial aneurysms are quite common. The main categories of aneurysm are abdominal aortic aneurysm (AAA), thoracic aortic aneurysm (TAA), and cerebral aneurysm.

The aorta is the large artery that carries blood from the hearts left ventricle and gives off branches that supply the body. AAA is an aneurysm in the abdominal portion of the aorta, meaning the part of the descending aorta downward from the diaphragm that divides the chest (thoracic) and abdominal cavities. TAA is an aneurysm in the thoracic aorta, which includes the ascending aorta (the portion of the aorta that extends upward from the aortic annulus that connects the aorta to the left ventricle), the aortic arch (the part that curves upward and then down), and the part of the descending aorta above the diaphragm (the descending thoracic aorta), though usually with a TAA were talking about the ascending aorta and aortic arch. A cerebral aneurysm is an aneurysm in the brain. While AAA, TAA, and cerebral aneurysms are the most common aneurysm categories, aneurysms also can occur in the wall of the heart itself, and in arteries supplying organs, walls of body cavities, and limbs. In pregnancy, for instance, cases have been reported of aneurysms in arteries supplying the kidneys and spleen, although the main concern surrounds the three aneurysm categories listed above.

How common are aneurysms during pregnancy?

Aneurysms are thought to be fairly common in adults of all ages and thus occur during pregnancy. It is difficult to estimate the actual prevalence because most aneurysms are thought not to produce any symptoms. Aneurysms are discovered, either when they produce symptoms, for instance, if they are pushing on something, or if the body is being imaged for another reason. Cerebral aneurysms are a particular issue in pregnancy, because these aneurysms occur much more often in women than in men, whereas the opposite is true for aortic aneurysms. Factors that increase your risk of having an aneurysm include high blood pressure, smoking, atherosclerosis, and certain genetic conditions of connective tissue, such as Ehlers-Danlos syndrome and Marfan syndrome. However, with Marfan syndrome, the main risk is not for a true aneurysm. Still, a special type called a dissecting aneurysm is part of a larger defect that also includes separation of the inner and middle layers of the artery wall. Additionally, a genetic condition called autosomal dominant polycystic kidney disease (ADPKD) is associated with an elevated risk of a cerebral aneurysm. Because a great but unknown number of people are thought to harbor asymptomatic aneurysms, it is also hard to compute the percentage of aneurysms that produce problems, the worst one being that the aneurysm ruptures.

How is an aneurysm during pregnancy diagnosed?

TAA and AAA can be diagnosed with imaging procedures, such as ultrasound of the heart or abdomen, computed tomography (CT) scanning, or magnetic resonance imaging (MRI) of the chest or abdomen. Cerebral aneurysm is diagnosed using CT angiography, magnetic resonance (MR) angiography, or cerebral angiography.

Does aneurysm cause problems during pregnancy?

Most aneurysms go unnoticed, but there is some concern that changes in the body, such as the changes that occur in pregnancy, may cause a small aneurysm to grow, or otherwise change. Complications that can occur from aneurysms include pushing on nearby structures, such as structures within the brain and formation of blood clots. However, the greatest concern is that an aneurysm will rupture, causing hemorrhage. In cerebral aneurysms, rupture leads to whats called subarachnoid hemorrhage (SAH), which threatens life, as does rupture of an aneurysm in the abdomen or chest. A lot of controversy surrounds the assessment of risk that an aneurysm will rupture. The known risk factors are large size of the aneurysm (in the brain, for instance, aneurysm less than 5 millimeters has been thought to be lower risk, but this too is controversial), high blood pressure, smoking, presence of daughter aneurysms (an aneurysm that balloons out from another aneurysm), various other features of aneurysm shape, and location of the aneurysm in the posterior (back) region of the brain rather than the anterior region. In the aorta, an aneurysm is considered to be present if the diameter is more than 3mm and considered to be a greater risk as the size increases further.

Does aneurysm during pregnancy cause problems for the baby?

Yes, because if it ruptures, it threatens the mothers life. Thus, the assessment of the mothers risk affects the baby.

What to consider about taking medications when you are pregnant or breastfeeding:

  • The risks to yourself and your baby if you do not treat the aneurysm
  • The risks and benefits of each medication you use when you are pregnant
  • The risks and benefits of each medication you use when you are breastfeeding

What should I know about using medication to treat aneurysm during pregnancy?

Medications are given to lower blood pressure and to prevent the aneurysm from growing. Such medications, the main ones being beta-blockers, can be chosen that are safe in pregnancy.

Who should NOT stop taking medication for aneurysm during pregnancy?

If you have an aneurysm during pregnancy that your doctor finds is at risk for rupture, taking the medication is a matter of life and death, so no one should stop taking the medication until it is ended by the order of your physician.

What should I know about choosing a medication for my aneurysm during pregnancy?

It is important to stay in communication with your health care provider as the release of new studies over time can change the outlook on the role of specific medications during pregnancy.

You may find Pregistrys expert reports about the medications to treat this condition here. Additional information can also be found in the sources listed below.

What should I know about taking a medication for my aneurysm when I am breastfeeding?

Medications are given to lower blood pressure and to slow the heart. Usually, such medications can be chosen that are safe for nursing mothers.

What alternative therapies besides medications can I use to treat my aneurysm during pregnancy?

Aneurysms that are considered to be at risk, either because of their size or other factors require definitive treatment in the form of either open surgical procedures, or endovascular treatment in which the aneurysm is treated with instruments inserted through tubes in the blood vessels. In the case of cerebral aneurysm, brain surgery can be performed to clip the aneurysm, meaning that little clamps are applied that close off the entrance into the aneurysm from the blood vessel. Alternatively, cerebral aneurysm can be treated with an endovascular procedure that uses coils to block blood from entering the aneurysm. With some of the hardware that is inserted, such as the clips, there is some concern that they will be affected if you later get magnetic resonance imaging (MRI). Even with clips made from titanium, which is muc
h less magnetic than iron-based materials, it is recommended that all imaging be performed in the same medical center where the clipping has been performed so that all of the details are known.

What can I do for myself and my baby when I have an aneurysm during pregnancy?

It is very important to follow the instructions of your physician.

Resources for aneurysm in pregnancy:

For more information about aneurysm during and after pregnancy, contact (800-994-9662 [TDD: 888-220-5446]) or contact the following organizations:


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Last Updated: 28-12-2019
General information

It is very common for women to worry about having a miscarriage or giving birth to a child with a birth defect while they are pregnant. Many decisions that women make about their health during pregnancy are made with these concerns in mind.

For many women these concerns are very real. As many as 1 in 5 pregnancies end in a miscarriage, and 1 in 33 babies are born with a birth defect. These rates are considered the background population risk, which means they do not take into consideration anything about the health of the mom, the medications she is taking, or the family history of the mom or the baby’s dad. A number of different things can increase these risks, including taking certain medications during pregnancy.

It is known that most medications, including over-the-counter medications, taken during pregnancy do get passed on to the baby. Fortunately, most medicines are not harmful to the baby and can be safely taken during pregnancy. But there are some that are known to be harmful to a baby’s normal development and growth, especially when they are taken during certain times of the pregnancy. Because of this, it is important to talk with your doctor or midwife about any medications you are taking, ideally before you even try to get pregnant.

If a doctor other than the one caring for your pregnancy recommends that you start a new medicine while you are pregnant, it is important that you let them know you are pregnant.

If you do need to take a new medication while pregnant, it is important to discuss the possible risks the medicine may pose on your pregnancy with your doctor or midwife. They can help you understand the benefits and the risks of taking the medicine.

Ultimately, the decision to start, stop, or change medications during pregnancy is up to you to make, along with input from your doctor or midwife. If you do take medications during pregnancy, be sure to keep track of all the medications you are taking.

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