Cardiomyopathy

INFORMATION FOR WOMEN WHO HAVE CARDIOMYOPATHY DURING PREGNANCY OR BREASTFEEDING

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 cardiomyopathy during pregnancy?

Cardiomyopathy is a set of diseases in which the heart muscle (myocardium) has difficulty contracting with enough force to pump blood through the body, when the difficulty cannot be explained by an underlying condition, such as heart valve problems or high resistance to blood flow in arteries. As a result, there is a low ejection fraction, meaning that an abnormally low amount of blood is pumped from the ventricles compared to how much blood is in the ventricles prior to the contraction. If this gets progressively worse, it becomes a situation known as heart failure. Cardiomyopathy can happen for a variety of reasons, leading to various subtypes of cardiomyopathy outside of pregnancy, the main ones being dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), and restrictive cardiomyopathy (RCM). All of these subtypes of cardiomyopathy, of course, could complicate pregnancy. However, there is also cardiomyopathy specific to pregnancy, a type of DCM called peripartum cardiomyopathy (PPCM) or postpartum cardiomyopathy, which can develop during the final weeks of pregnancy and up to approximately five months after you give birth.

How common is cardiomyopathy during pregnancy?

The incidence of PPCM varies depending on geographic location and socioeconomic status, with rates higher than 1 case per 100 births reported in Nigeria and 1 case per 20,000 births occurring in Japan. Rates reported for HCM vary from as high as 1 per 500 people (whether pregnant or not) down to 1 per 3,000, while the other main subtypes of cardiomyopathy mentioned above are more rare, especially RCM. Being above age 30, when you are pregnant, puts you at a higher risk of developing PPCM compared with younger women.

How is cardiomyopathy during pregnancy diagnosed?

As noted earlier, PPCM is a type of dilated cardiomyopathy. This means that the heart gets larger as it gets weaker, which is something that can be seen on a simple chest x-ray (CXR), which is one test that will be performed. You should not worry about radiation exposure to the fetus, because it is a very low radiation dose and modern x-rays are very narrowly focused and aimed. You will also be given an electrocardiogram (ECG), which measures electrical activity in the heart from different directions, an echocardiogram, a stress test on a treadmill, and a range of other tests that may include cardiac magnetic resonance imaging (MRI), cardiac catheterization in which instruments are passed into your heart through a tube inserted through a vein in your leg, and various blood tests and genetic tests. A diagnosis of PPCM can be made if you meet three criteria: Heart failure beginning any time from a month before delivery until 5 months after delivery; an ejection fraction below 45 percent as measured during echocardiography (normal ejection fraction ranges from 55 to 70 percent and often is far above 70 percent in trained athletes); your physicians are able to rule out other possible causes of the low ejection fraction and heart failure.

Does cardiomyopathy cause problems during pregnancy?

Yes. This is a very serious condition since heart failure can be fatal, and often the only effective treatment involves heart surgery, either to install a ventricular assist device (a machine that augments the hearts pumping) or to perform heart transplantation. Such procedures generally are not possible while you are pregnant, but can be performed after the baby is delivered.

Does cardiomyopathy cause problems for the baby?

Yes, because cardiomyopathy can be fatal to the mother, there is an extreme risk of fetal death.

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 cardiomyopathy
  • 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 cardiomyopathy during pregnancy?

There is not a medication specific for PPCM, which means that the heart failure will be treated in a similar way to how any heart failure of this type (called systolic heart failure, failure of the heart to produce a powerful enough systolic pressure through contraction of the ventricles) is treated. This means that you will be admitted to the intensive care unit (ICU) for extensive monitoring and also to receive treatment that will include medications. These include what are called loop diuretics (drugs that make you excrete water from the blood to reduce the load that the heart must push), which are safe during and after pregnancy, medications that widen blood vessels (nitroglycerin and nitroprusside, also okay during pregnancy) and, if needed, medications that strengthen the hearts contraction (dobutamine or milrinone). If the ejection fraction is very low (less than 35 percent), you also will need low-molecular-weight heparin (LMWH, also safe in pregnancy) to thin the blood, because large amounts of blood remaining in the left ventricle after contraction means that thrombi (blood clots) can form in the ventricle. Once you deliver, you can be switched from LMWH to a stronger blood thinner called warfarin (warfarin cannot be used in the weeks before delivery, because it can cause hemorrhage in the babys brain).

Who should NOT stop taking medication for cardiomyopathy during pregnancy?

If your heart failure is stabilizing or improving with medications, you cannot stop the treatment. Still, any decisions on changing or adjusting medications and doses can be made in consultation with your physicians, including your cardiologist and obstetrician.

What should I know about choosing a medication for my cardiomyopathy 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 cardiomyopathy when I am breastfeeding?

Very few data are available on the effects of blood vessel opening drugs, such as nitroglycerin and nitroprusside, on nursing infants. LMWH and warfarin are safe in nursing mothers, but loop diuretics may reduce your milk production because they lower the amount of water in your blood.

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

If you have a low ejection fraction and heart failure, you need medications. Rather than being alternatives to medication, there are other therapies to go along with medications. These therapies include mechanical ventilation with 100 percent oxygen and left ventricular assist devices, which help the heart to pump blood. One lifestyle recommendation that physicians may give you is to reduce your intake of dietary salt.

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

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

Resources for cardiomyopathy in pregnancy:

For more information about cardiomyopathy during and after pregna
ncy, contact http://www.womenshealth.gov/ (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.