Rheumatic Fever: Issues for Pregnancy

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Rheumatic fever is common in the poorest countries of the world, such as in sub-Saharan Africa. It is rare in developed countries, although one potential risk for rheumatic fever that may be emerging in developed countries is a growing culture among certain people that rejects evidence-based medicine in favor of so-called “natural” treatments. Rheumatic fever is an inflammatory condition that can occur as a complication of infection with a category of bacteria called group A β-hemolytic Streptococcus, abbreviated GAS. Usually, the GAS infection leading to Rheumatic fever is streptococcal pharyngitis, known commonly as a strep throat. Rheumatic fever also can result from certain other GAS conditions, such as scarlet fever. Most GAS infections are of the species Streptococcus pyogenes, from which rheumatic fever develops, only when the infection is not treated appropriately with antibiotics medicines. As the immune system fights off the bacteria, immune cells and antibodies that they produce attack certain body tissues that have been damaged by the GAS, particularly in the heart, nervous system, skin, and joints. It takes 2 to 4 weeks after the strep infection before the immune attack makes the person sick, but then the following symptoms can develop:

  • Arthritis
  • Fever
  • A particular kind of rash
  • Inflammation of all layers of the heart (pancarditis)
  • Sydenham chorea: Also called “chorea minor” and “ Vitus dance”, this is a fast, jerking, uncoordinated movement of the hands, feet, and face. It results from the immune system damaging areas in the brain called the basal ganglia. Specifically, the damage is to cells of a basal ganglia structure called the corpus striatum.

In this early form, the condition is known as acute rheumatic fever (ARF), which typically strikes children ages 5-15, rather than women of child-bearing age. However, rheumatic fever is most notorious for long-term effects that can develop in the heart, known as rheumatic heart disease (RHD). This condition causes inflammation across all layers of the heart, known as pancarditis. Over the course of decades, the damage disrupts the function of the myocardium (the thick, muscular layer of the heart), which can lead to heart failure. It also damages the inner layer of the heart, making the person highly susceptible to infections of that layer. RHD generates what are called vegetations on heart valves, and also damages fibrous strings that normally help keep the valve leaflets from prolapsing (going backward when they close to stop backward blood flow).

RHD is a significant issue for pregnancy, because pregnancy can exacerbate cardiac problems, due to a large increase in the volume of blood that develops as pregnancy advances. These problems include infective endocarditis (IE), if you suffer a bacterial infection, which can happens from simple procedures (such as dental work), if you do not receive antibiotics in advance. The problems also include heart valve problems. The mitral valve (through which blood passes between the heart’s left atrium and left ventricle) is affected most commonly. The aortic valve (through which blood passes from the left ventricle to the aorta) often is affected as well. In particular, RHD produces mitral stenosis (MS; narrowing of the mitral valve) and mitral valve prolapse (MVP). If severe, MS can lead to pulmonary hypertension (high pressure in the pulmonary circulation and in the pulmonary artery, and often in the right ventricle of the heart). This can lead to heart enlargement and heart failure, but heart failure also can result from rheumatic fever damaging of the myocardium itself. Heart failure furthermore produces pulmonary edema (fluid in the lungs). Other complications include atrial fibrillation (quivering of the heart’s atria, instead of pumping action), which, in turn, can cause blood clots.

MS and other effects of RHD can result in premature labor and delivery, intrauterine growth retardation (the fetus grows too slowly in the womb), low birth weight, fetal death, and death of the newborn soon after birth. There is some evidence that these problems also can happen in pregnant women with MVP.

Rheumatic fever is completely preventable. All GAS infections, such as streptococcal pharyngitis must be treated with an appropriate antibiotic regimen. If you are allergic to one type of antibiotic, another effective type can be selected for you. Acute rheumatic fever can be treated with non-steroidal anti-inflammatory drugs (such as ibuprofen), salicylates (such as aspirin), or corticosteroids.

In cases of rheumatic heart disease during pregnancy, this is treated based on the complications occurring in the heart. Depending on your condition, treatment may include slowing the heart rate, with a type of drug called a beta blocker, or another type of drug called a calcium channel blocker. It also may include a group of drugs called nitrates. For those with valve conditions causing atrial fibrillation that can produce blood clots, blood thinning drugs are given. Certain blood thinning medicines must be replaced during pregnancy with other medicines.

As for breastfeeding, the American Academy of Pediatrics suggests that beta-blockers are safe during nursing of neonates, but that low doses should be considered until you have finished the breastfeeding period. A pregnancy-save blood thinner called low molecular weight heparin is known to enter breastmilk, but in very tiny amounts. This is not harmful, because the medicine is simply degraded in the infant’s digestive system.

David Warmflash
Dr. David Warmflash is a science communicator and physician with a research background in astrobiology and space medicine. He has completed research fellowships at NASA Johnson Space Center, the University of Pennsylvania, and Brandeis University. Since 2002, he has been collaborating with The Planetary Society on experiments helping us to understand the effects of deep space radiation on life forms, and since 2011 has worked nearly full time in medical writing and science journalism. His focus area includes the emergence of new biotechnologies and their impact on biomedicine, public health, and society.

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