Pregnant with heart disease

Heart conditions are a leading cause of maternal death associated with pregnancy, and they are seen in up to one in 25-50 pregnant women. If you have heart disease, you may be considered high-risk and working closely with a high-risk obstetrician (perinatologist or maternal-fetal Medicine specialist) and a cardiologist will help you to achieve a good outcome for you and your baby.

It used to be that over 90% of pregnant women with heart disease had ‘rheumatic heart disease’, injuries of the heart and heart valves brought upon by rheumatic fever. Rheumatic fever is a rare but potentially life-threatening infection and complication of untreated strep throat, caused by streptococcus A bacteria. Because of improved care and antibiotic treatment, the number of pregnant women with heart disease due to rheumatic fever has decreased significantly over the last decades. Today, the most common form of cardiac disease in pregnant women are congenital heart conditions, which are seen in over 1 in 3 women with heart disease in pregnancy.

Symptoms of heart disease

The first symptom of a heart condition is usually shortness of breath, dizziness, or chest pain. Many pregnant women normally complain about occasional shortness of breath, the inability to get enough air in, dizziness, and the inability to perform certain physical exercises. These complaints are usually normal and due to the increased load of blood volume on your heart, which increases up to 50% by the 28th weeks of pregnancy. If you have a weakened heart, it sometimes cannot tolerate the increased stress of pregnancy and becomes unable to function well.

Unfortunately, the same normal pregnancy symptoms can also mimic heart disease in pregnancy, and it can sometimes be difficult to distinguish what’s normal and what’s abnormal in pregnancy. 

How will you know that your symptoms are normal?

Let your doctor know right away if you:

• Experience shortness of breath especially if it’s out of the usual
• You feel uncomfortable
• You can’t do your normal physical activities anymore
• You experience chest pain
• You suddenly experience swelling in your body, specifically your arms and hands

A physical examination by your doctor will usually exclude heart disease. Sometimes an ultrasound examination of your heart called ‘echocardiogram’ is indicated to check your heart.

If a heart condition is diagnosed it’s classified:

• Which part of the heart is involved (a valve, the heart muscle, the lining of the heart, or if it’s an irregular heartbeat)
• How severe that part is damaged or abnormal
• If it’s congenital or acquired,
• How severe your symptoms are (New York Heart Association Classification of Heart Disease, see table).

Below is a table that shows a list of possible forms of heart disease:

• Congenital heart disease:  Someone who is born with one or more congenital heart defects usually because something went awry in the formation of the heart during prenatal development.  Such defects are quite common, occurring in about seven of every 1,000 births.
• Cardiac arrhythmia: Disturbances of the heart beating rhythm
• Coronary heart disease: Blockages in the coronary arteries resulting in a reduction in blood flow to the heart muscle, depriving it of vital oxygen
• Heart valve disease: The heart has four valves: the pulmonary, mitral, tricuspid and aortic. The valves open and close to direct blood flow between the heart's four chambers, the lungs and connected blood vessels. A defective valve may fail either to open properly, obstructing blood flow, or to close properly, allowing blood leakage. Congenital heart disease and various inflammatory and infectious conditions are among the causes of valve disorders.
• Pericardial disease: Any disease of the pericardium, the membranous sac surrounding the heart
• Myocardial heart disease:  Diseases of the heart muscle, or myocardium, are collectively referred to as primary myocardial disease, or cardiomyopathy.

New York Heart Associations’ functional classification of heart disease

Class I    No limitation of activities; no symptoms from ordinary activities.
Class II    Slight, mild limitation of activity; comfortable with rest or with mild exertion. More than ordinary physical activity results in fatigue, palpitation, dyspnea, or anginal pain
Class III    Marked limitation of activity; comfortable only at rest. Less than ordinary physical activity causes fatigue, palpitation, dyspnea, or anginal pain.
Class IV    Confined to bed or chair; any physical activity brings on discomfort and symptoms occur at rest. Symptoms of cardiac insufficiency or of the anginal syndrome may be present even at rest. If any physical activity is undertaken, discomfort is increased.

Over 90% of all heart conditions in pregnancy are class I or II and are therefore not involved with any significant risks.  while women with class III and IV heart disease have increased complications, and frequent hospital admissions may be indicated.

Most of the more severe conditions are diagnosed before pregnancy, and it’s unusual to first diagnose a severe heart condition in pregnancy. One of the more severe but very rare heart conditions, called ‘peripartum cardiomyopathy’, is seen only late in pregnancy, and after delivery. Only a few heart diseases are so severe that pregnancy is associated with a very high mortality rate to the mother. (see table below)

Maternal mortality associated with specific cardiac lesions

Low risk of maternal mortality (<1%)    Most Class I or II lesions of New York Heart Association (NYHA); Patent ductus arteriosus; Pulmonic/ tricuspid lesions; Septal defects   
Moderate risk of maternal mortality (5%-15%)    Most Class III or IV NYHA lesions, especially mitral stenosis; Tetralogy of Fallot Aortic stenosis; History of Myocardial Infarction (heart attack); Marfan syndrome with normal aorta
High risk of maternal mortality (25%-50%)    Eisenmenger's syndrome; Marfan syndrome with abnormal aortic root; Peripartum cardiomyopathy;  Pulmonary hypertension   

Heart disease can not only affect the mother’s body, but it can also affect the fetus. If the mother’s heart is unable to supply enough oxygen and other nutrition to fetus, the fetus will not grow enough and develop a condition called ‘intrauterine growth restriction’.

Here are some general guidelines for women with known heart disease in pregnancy:

• Find out exactly which heart disease it is.
• Find out about its effect on pregnancy and the effect of pregnancy on heart disease.
• See a high-risk obstetrician (Maternal-Fetal Medicine specialist) and a cardiologist if necessary
• If the mother has a congenital condition there is a risk that the fetus may have one too. If it’s only the mother that has a congenital heart disease, the risk of congenital heart disease in the baby is usually 2% to 5% (more than twice the risk in the general population), but it can be higher with certain conditions, or if one or more other siblings have a congenital heart disease too. A fetal echogram around 20-22 weeks can check if the fetus has heart disease.
• Avoid excessive weight gain, and eat a healthy diet
• Report any significant change in weight or any symptoms such as shortness of breath to your doctor.
• Avoid strenuous physical activity. Discuss with your doctor what you can or cannot do.
• Talk to an anesthesiologist before labor and before any procedures requiring anesthesia.
• During labor, delivery and specifically post-partum watch out for signs of heart failure.