The Risk of Aortic Dissection in Pregnancy

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Pregnancy puts you at a higher risk of having a cardiovascular event like a thromboembolism (a blood clot that travels to another part of the body), a heart attack, or a stroke. There are other, much more rare cardiovascular events that you are at increased risk for as well. One of those rare events is aortic dissection.

What is the Aorta?

The aorta is the large artery that carries blood directly away from the heart. Because of its proximity to the heart, the aorta is subject to a lot of pressure each time the heart pumps. The heart is pumping the blood with a force strong enough to circulate it throughout the entire body. The aorta extends from the upper chest all the way down through the abdomen with multiple branching arteries to deliver blood to organs and tissues along the way.

The aorta, and every other blood vessel in the body, is made up of layers of tissue. The innermost layer is called the intima. The middle layer is called the media. The outer layer is called the adventitia. Aortic dissection occurs when a tear forms between the layers of the aorta. This is a medical emergency.

What is Aortic Dissection?

As stated above, aortic dissection is a tear between the layers of the aorta. This is a medical emergency because if blood is diverted through a tear in the largest artery in the body, it will not get to any of the other tissues and organs that need it. Furthermore, if the tear proceeds to rupture the outer wall of the aorta, the condition can rapidly deteriorate to death.

Why Does Pregnancy Put You at Increased Risk of Aortic Dissection?

During pregnancy, your body undergoes many changes to prepare for giving birth. These changes affect every single part of your body, including your heart and blood vessels. First, the amount of blood the heart must pump through your body increases by half. Because of the increase in the volume of blood, the heart must pump harder and faster. Second, because of the hormones relaxin and progestin, we see an increase in the flexibility of all your blood vessels. This flexibility does great to accommodate the increased blood volume, but it could also lead to stretching beyond what is physiologically appropriate. The vessels may be weakened, leading to an increase in the possibility of a tear.

Pregnancy puts you at increased risk of aortic dissection due to the following factors:

  • Increase in the amount of blood circulating through your body.
  • Increase in the force with which the heart must pump.
  • Increase in hormones that increase the pliability of the blood vessels leads to increased stretching and possible weakening of vessels.

Is Aortic Dissection Always Deadly?

Whether or not aortic dissection is deadly depends on two things: where the tear is located and whether or not the tear rips through the outer layer of the aorta.

Using the Stanford classification system, there are two types of aortic dissection based on their location. The first type is Type A. Type A aortic dissection occurs in the area of the aorta that is closer to the heart. This type typically requires surgery to repair and is more likely to lead to rupture. About 75% of aortic dissections are type A.

The second type is Type B. Type B aortic dissections occur farther away from the heart, usually in the abdominal aorta. Type B aortic dissections may not require surgical intervention and may be manageable with medicines. About 25% of aortic dissections are type B.

Type A Aortic Dissection:

  • Occurs proximal to (close to) the heart.
  • Typically requires surgical repair.
  • More likely to lead to aortic rupture.
  • Accounts for about 75% of all aortic dissections.

Type B Aortic Dissection

  • Occurs distal to (farther away from) the heart, usually in the abdomen.
  • May not require surgical repair.
  • May be managed medically.
  • Accounts for about 25% of all aortic dissections.

What are the Symptoms of Aortic Dissection?

Symptoms include:

  • Sudden onset tearing pain on the left side of your chest that may or may not extend to your upper back and/or neck.
  • Sudden onset pain in your abdomen.
  • Shortness of breath.
  • Loss of consciousness.
  • Symptoms that may be consistent with stroke, like one-sided paralysis or difficulty forming words.

If you experience any of these symptoms while pregnant, call 911.

Janette DeFelice
Dr. Janette DeFelice is a writer currently focusing on how the changing environment affects our health. She holds a Doctor of Medicine degree from Chicago Medical School where she taught clinical and diagnostic skills to beginning medical students, and a Master’s degree in Humanities from the University of Chicago. She also has a Bachelor’s degree in Political Science. Her writing can be seen online at BeTheChangeMom, ChicagoNow, and Medium, and she’s very excited to have published her first novel, Delia Rising: A Ballet in Three Acts. She lives in Chicago’s west suburbs with her school-age twins, her husband, and a family cat named Clara Barton.

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