Pregnancy and the Heart
Pregnant heart patients need special care during pregnancy and delivery to avoid a pregnancy complication. Because pregnancy places an increased demand on the expectant mother’s heart, a woman with existing heart disease is at increased risk for heart problems. This is why women with heart disease or other heart conditions are encouraged to discuss pregnancy with their physicians before deciding to become pregnant.
Some heart-related conditions carry greater dangers for the mother and/or the child than others. Good prenatal care, which includes close physician participation throughout the pregnancy, increases the chances of a healthy baby and mother.
Heart Risks During Pregnancy
Heart-related conditions may also develop in otherwise healthy women who become pregnant. These gestational heart-related problems include:
- Peripartum cardiomyopathy. This is caused due to complications from pregnancy. It is one of the several gestational heart-related conditions, it most often occurs in women over the age of 30 during the last three months of their pregnancy or within four to six months after delivery. It is also more common among women who have had multiple children, are carrying twins (multiple birth) or who have preeclampsia. Peripartum cardiomyopathy can be a serious or even life-threatening risk for the mother and can also put her unborn child at risk. In some women, heart function does not return to normal after pregnancy.
- Pregnancy-induced hypertension (high blood pressure). High blood pressure during pregnancy can affect the supply of oxygen to both mother and the fetus. This can, in turn, increase the risk of stroke and seizures in the mother and delay the physical development in the fetus. Smoking, being overweight, having diabetes and having a family history of high blood pressure are some risk factors for pregnancy-induced hypertension. A multiple birth also increases the risk. Pregnancy-induced hypertension usually clears up within six weeks of giving birth, however, more studies are needed to see if the mother is at long-term risk of developing hypertension later in life.
- Preeclampsia. This condition is closely linked to pregnancy-induced hypertension. It typically occurs after the 20th week of pregnancy and is characterized by elevated blood pressure and protein in the mother’s urine, which is the result of kidney problems. Preeclampsia can affect the mother’s kidneys, liver and brain. It may also cause seizures. In this case, it is called eclampsia and is the second-leading cause of maternal death.
- Pregnancy-induced diabetes (gestational diabetes). A condition in which women develop type 2 diabetes during pregnancy, returning to normal after delivery. Studies have shown that one-half of those with gestational diabetes developed type 2 diabetes again within the next 15 years. These women are also more likely to have gestational diabetes with a future pregnancy.
- Strong, fast, “galloping” heart beat (palpitations). Pregnancy places a greater demand on the heart. This could result in episodes of rapid heartbeat (tachycardia) or palpitations. Generally, these are common, normal occurrences. However, women are advised to see their physicians in order to rule out serious conditions.
- Varicose veins - An increase in blood volume is a normal part of pregnancy. Along with quite obvious physical growth, these changes place a stress on the leg veins. As a result, veins in the leg can swell and bulge. The risk for developing varicose veins increases if a woman is overweight and/or has a family history of varicose veins.
- Blood clots - Blood clots are the leading cause of death in pregnant women. They may form in the superficial veins of the legs (superficial vein thrombosis) or in the deep veins of the leg (deep vein thrombosis). If a blood clot breaks free and travels through the body, it can clog another vessel. If this happens in the lungs it is called a pulmonary embolism. If this happens in the brain, it is called a stroke. Women who are at risk for blood clots may be given an anticoagulant (e.g. heparin) to prevent blood clots from forming.
- Amniotic fluid embolism. A very rare type of embolism known to occur when placental membranes rupture (e.g., difficult labor, Cesarean section). Amniotic fluid travels to the lungs, where it can cause shock, tachycardia and sudden cardiac death.
- Heart murmur. An abnormal heart sound that results from the turbulent flow of blood through the heart. Most heart murmurs are harmless. In pregnant women, an increased blood flow through the heart may cause a heart murmur. However, heart murmurs may also indicate an underlying heart condition, such as a problem with the heart valve.
- Arrhythmias. An abnormal heartbeat that may be unusually fast (tachycardia) or unusually slow (bradycardia). Arrhythmias can develop during pregnancy in women with a normal heart and those with undiagnosed heart disease. In most cases treatment is not required.
Women who develop a heart condition during pregnancy may require the care of a cardiologist for the duration of their pregnancy.
Conditions Affecting the Baby
A heart defect or other congenital heart disease could also develop in the fetus. Congenital heart diseases include abnormalities with the structure of the heart, including the valves and chambers, and problems with the vessels that carry blood to and from the heart. In the vast majority of patients, the cause of congenital heart disease is unknown. However, there are some risk factors that have been associated with a higher rate of congenital heart disease. These risk factors include:
- Chromosomal or genetic abnormalities (e.g., Down syndrome) in the child
- Certain medications taken during pregnancy
- Alcohol or drug abuse during pregnancy
- Exposure to certain environmental agents (e.g., some pesticides, lead)
- Maternal viral infection, such as rubella (German measles) in the first trimester
- Maternal fever early in pregnancy or around conception
- Maternal diabetes (that is, pre-existing diabetes, and not gestational diabetes)
- Maternal obesity
- Poor nutrition (e.g., from eating disorders, unbalanced diet)
- Age. The mother’s age has an effect on the pregnancy and on the developing fetus. Mothers in their 30s and 40s are monitored more closely than others.
What is Needed?
For all pregnant women, especially those whose pregnancies are considered high-risk, healthy habits and precautions are encouraged. These include:
- Avoid smoking as much as possible, including passive smoking.
- Avoid intake of alcohol and illegal drugs.
- Take a prenatal multivitamin before conception and throughout the pregnancy. Most prenatal vitamins include folic acid (folate), a B-vitamin known to help prevent certain birth defects.
- Take medication (both prescription and over-the-counter) with a physician’s approval only.
- Eat a nutritious diet.
Women are also encouraged to speak with a cardiologist about which of the four New York Heart Association (NYHA) classifications would best characterize their pregnancy. Women in Class I and Class II are less likely to experience serious complications than women in Class III or Class IV.
In order to determine the best course of therapy, physicians often assess the stage of heart failure according to the New York Heart Association (NYHA) functional classification system. This system relates symptoms to everyday activities and the patient's quality of life.
Class I (Mild)
No limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation, or dyspnea (shortness of breath).
Class II (Mild)
Slight limitation of physical activity. Comfortable at rest, but ordinary physical activity results in fatigue, palpitation, or dyspnea.
Class III (Moderate)
Marked limitation of physical activity. Comfortable at rest, but less than ordinary activity causes fatigue, palpitation, or dyspnea.
Class IV (Severe)
Unable to carry out any physical activity without discomfort. Symptoms of cardiac insufficiency at rest. If any physical activity is undertaken, discomfort is increased.