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 endocarditis during pregnancy?

The endocardium is the innermost of three layers of tissue that comprise the heart. Consisting of endocardial cells (similar to endothelial cells that line the inner walls of blood vessels), the endocardium lines the inside of the hearts four chambers and also covers the hearts valves. The term endocarditis refers to a severe, life-threatening situation in which there is inflammation occurring somewhere along the endocardial layer, which is to say on the inner lining of a heart chamber, or on a valve. Very often, endocarditis involves at least one valve, typically the mitral valve. Also called the bicuspid valve or the left atrioventricular valve, the mitral valve is the passageway between the hearts left atrium and left ventricle. In more rare cases, endocarditis can occur on a different valve, such as the aortic valve, the valve that connects the left ventricle with the aorta, the large artery that carries blood from the heart to various arteries.

There are two main categories of endocarditis. Usually, the term endocarditis refers to what doctors call infectious endocarditis (IE), which is endocarditis resulting from a bacterial infection. The other category of endocarditis is called nonbacterial thrombotic endocarditis (NBTE). Whereas NBTE involves a clotting agent called fibrin building up on valves. Usually, IE develops because of some structural abnormality in a heart chamber or on a valve, making it easier for certain bacteria to get stuck on the damaged area and develop into a bacterial colony. Classically, throughout the world in the days before antibiotics, and still today in developing countries, the most common way for this to happen is changes on and around the mitral valve due to rheumatic fever, resulting from an infection with Streptococcus bacteria. In such cases, before suffering endocarditis, people with rheumatic heart disease, including pregnant women, have had whats called mitral valve prolapse, meaning that the leaflets of the valve would be floppy and parachute backward into the left atrium. If this gets really bad, the valve could also be leaky, causing whats called regurgitation of blood. Sometimes, calcium deposits have formed on parts of the valve, and this can happen with other valves, too, in addition to the mitral valve.

Apart from Streptococcus, IE can also be caused by Staphylococcus and other types of bacteria, and there are various other pathways to endocarditis apart from rheumatic heart disease. Thus, it is possible for women in their childbearing years to develop endocarditis, although the condition is quite rare.

How common is endocarditis during pregnancy?

Both infectious endocarditis and non-infectious endocarditis are very rare in pregnancy. Infectious endocarditis has been reported to occur at rates of 12 to 25 cases per every 200,000 deliveries. The number of IE cases resulting from rheumatic heart disease has been decreasing over the years, along with the number of cases with Streptococcus as the causative bacteria. However, more cases of IE are due increasingly to Staphylococcus and other types of bacteria, while a higher proportion of endocarditis is of the NBTE type. Risk factors include having prosthetic devices implanted in blood vessels and the heart, including pacemakers and defibrillators, as well as prosthetic heart valves. Other risk factors include being infected with HIV (the virus that causes AIDS), intravenous drug use (IDU), having congenital heart disease, and other structural heart abnormalities, such as mitral valve prolapse.

How is endocarditis during pregnancy diagnosed?

Endocarditis is diagnosed through a combination of findings on the physical exam, blood tests for microorganisms, and a heart imaging test called echocardiography. Classically, the physical signs contributing to the diagnosis have included murmurs, heard by the examiner through the stethoscope, but this is becoming less important compared with echocardiography, which is becoming increasingly more capable. Tests for bacteria from blood samples include blood cultures, but also may include tests for DNA of particular microorganisms and other molecular tests. You also may receive testing for fungus, especially if there is a suspicion that you have NBTE. Doctors may also order various immunological tests, and there may be tests of your skin and eyes. Formal diagnosis for IE is made based on criteria known as the Modified Duke Criteria, involving results of tests for bacteria in the blood, findings on echocardiography, immunological testing, and other factors.

Does endocarditis cause problems during pregnancy?

Yes. First of all, you will suffer symptoms, including fever and chills, breathing trouble, night sweats, and joint pain, and a range of other symptoms. Endocarditis is a very serious condition. The condition can produce a range of severe complications, including emboli (materials traveling in the blood until they are trapped somewhere and cause blood vessel obstructions), aneurysms (weak areas of blood vessel walls which are at risk of rupture), and bleeding in organs, including the brain. Even with the best therapy, IE has been reported to have a 25 percent mortality rate. Endocarditis also can occur as a post-pregnancy condition, beginning at the end of pregnancy, or after you have delivered, as well as beginning during pregnancy.

Does endocarditis cause problems for the baby?

Yes, because endocarditis 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 endocarditis
  • 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 endocarditis during pregnancy?

Endocarditis must be treated with intensive antibiotic therapy. Various antibiotic regimens can be selected that are fairly safe in pregnancy. Depending on your condition, including the balance between your risk for clots versus your risk of hemorrhage, you may or may not require blood-thinning medications. Depending on the stage of pregnancy, such blood-thinning medications can include low molecular weight heparin (LNWH) and/or aspirin. In severe cases, the drug warfarin might be given in mid-pregnancy as a blood thinner. Still, it is contraindicated both in early pregnancy (due to the risk of birth defects) and in late pregnancy (due to the risk of bleeding in the brain for the baby).

Who should NOT stop taking medication for endocarditis during pregnancy?

Endocarditis is a potentially fatal condition whose elimination requires antibiotics, and often other treatments as well.

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

LMWH and warfarin are safe for nursing mothers, as are various antibiotic regimens.

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

In addition to antibiotic therapy (not to replace it, however), you may also require procedures, such as surgery on a valve.

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

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

Resources for endocarditis in pregnancy:

For more information about endocarditis during and after pregnancy, contact http://www.womenshealth.gov/ (800-994-9662 [TDD: 888-220-5446]) or contact the following organizations:


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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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