Navigating pregnancy with a heart condition: What you need to know
February 20, 2025
If you have a pre-existing heart condition, the normal pregnancy-related strains on your cardiovascular system – such as increases in heart rate, blood volume, and the “squeeze” action that pumps blood – must be considered before you plan for pregnancy. Many conditions are associated with good outcomes with the support of a specialized care team. But some are associated with a very high risk of heart failure or death, and carrying a pregnancy is specifically not recommended. You need to know where you stand.
A pre-existing heart condition is a problem with the way your heart is formed or functions that exists prior to pregnancy. This could be a congenital abnormality with the valves or blood vessels or poorly developed or underdeveloped areas of the heart muscle. Congenital means you were born with the condition. Other conditions happen over time, such as coronary artery disease, cardiomyopathy, or pulmonary hypertension. Isolated high blood pressure is also a preexisting cardiovascular condition.
Women with pre-existing heart conditions generally are considered to have a high-risk pregnancy, which means you and the baby need extra or specialty care for the best chances of a healthy outcome. Some experts who may be part of your care team include:
- Your prenatal care provider, likely an obstetric physician
- A cardiologist with special training in cardiology and pregnancy care
- A maternal-fetal medicine (MFM) physician who specializes in managing high-risk pregnancies – MFM doctors are available at any UT Southwestern location where we offer pregnancy care.
UT Southwestern is a Level 4 maternal health center, the highest designation in the state of Texas. This means we care for patients with the most complex pregnancies, and we offer advanced screening, testing, and the most up-to-date interventions needed to have good outcomes with multispecialty care coordination.
Let’s discuss some of the common pre-existing heart conditions that can affect pregnancy and how we support women to make the best decisions for their current and future health.
Which conditions could affect pregnancy?
The World Health Organization has an evidence-based risk stratification system that assesses risk of pregnancy called the Modified WHO Classification of Maternal Cardiovascular Risk (mWHO). Some heart conditions in mWHO Class I or II likely do not pose a significant risk in pregnancy with proper care. Examples include mitral valve prolapse, prior ventricular or atrial septal defect that was repaired or even unrepaired if it is small, or mild arrhythmia (irregular or fast heartbeat) that is controlled.
However, with certain cardiovascular conditions, the heart will not tolerate the additional stress of pregnancy. Existing symptoms may worsen or create new complications such as progression to heart failure or even death. These include progressively increased risk with conditions in mWHO Class II-III, where the specifics of the condition may allow for good outcomes with extra care. But those conditions in Class III and specifically in Class IV have pregnancy-associated risks that most would consider unacceptable.
Heart muscle and valve conditions
These types of conditions include:
- Severe valvular disease, such as mitral stenosis or aortic stenosis, that narrows the openings of vital heart valves.
- Cardiomyopathy, a disease category with many possible underlying causes that weaken the heart muscle, diminishing the ability to pump blood effectively or significantly. An example is hypertrophic cardiomyopathy, in which the heart muscle thickens and may or may not narrow the exit path of blood from the heart.
- Aortic disease with the risk of an aneurysm or aortic dissection.
- Sustained arrhythmias, such as ventricular fibrillation or ventricular tachycardia, that significantly disrupt blood flow.
- Ischemic heart disease, also known as coronary artery disease, that narrows the arteries within the heart and may have caused previous damage to the function of the heart muscle.
Congenital heart defects that cause anatomical abnormalities
Congenital heart diseases include:
- Severe unrepaired ventricular septal defects (VSDs) or atrial septal defects that cause a hole in the wall separating the two chambers of the heart. Eisenmenger syndrome is a specific, life-threatening condition that can result from a long-term, unrepaired larger VSD because the prolonged volume strain on the right heart leads to pulmonary hypertension.
- Hypoplastic left heart syndrome, in which the left side of the heart is underdeveloped and cannot pump a sufficient volume of blood.
- Coarctation of the aorta, a narrowing of the main artery connecting directly to the heart.
Surgical repairs to heart malformations
Past cardiovascular surgeries that could complicate pregnancy include:
- Valve replacement, specifically mechanical prosthetic valves since they require lifelong use of a specific anticoagulation therapy that can cause fetal malformations.
- Coronary bypass, with risk primarily related to the underlying condition that led to a young woman experiencing this and the potential damage caused if there was a prior heart attack or ischemic event.
- Aortic dissection repair, with risk also highly related to the underlying condition that led to this and how the vessel functions after repair.
Pulmonary hypertension
Primary pulmonary hypertension is a pulmonary vascular disease that causes dangerously high blood pressure in the pulmonary arteries, which carry blood from the heart to the lungs, causing the heart to have to pump harder. While this can be a primary pulmonary condition at baseline, it causes heart failure over time and has to be very closely managed. There is also secondary pulmonary hypertension such as Eisenmenger syndrome, or it can be secondary to other medical conditions such as sleep apnea, sarcoidosis, or prior pulmonary embolism. Regardless of underlying etiology, this is a very high-risk condition for pregnancy.
Carrying a baby while living with cardiovascular disease inherently requires visiting your pregnancy care team frequently and monitoring your pregnancy for worsening symptoms or new concerns.
Risks for the baby
There are other possible risks to consider when talking with your health care provider.
Pre-term delivery
Early deliveries are more common among women with cardiovascular issues, often due to worsening maternal status and the need to remove the strain of pregnancy to avoid further deterioration. In some cases, we recommend inducing labor early to avoid the potentially hazardous strain on the mother’s heart during the final weeks of pregnancy.
Another reason is fetal growth restriction (FGR), a condition in which the baby is small for gestational age and has a higher risk of breathing problems or low blood sugar. This is more common when the mother’s heart can’t provide adequate blood flow through the placenta.
Certain medications
Specific antihypertensive medications called ACE-inhibitors (names generally end in “pril”) or angiotensin receptor blockers or ARBs (names generally end in “-sartan”) as well as some blood thinners – including Coumadin (warfarin) – are not safe in pregnancy due to risk for fetal malformations. Cholesterol-lowering medications (statins) also are not recommended for most pregnant patients.
Genetics
Several maternal conditions are also associated with an increased risk for having offspring that are also affected. Congenital cardiac malformations are often considered multifactorial, but the odds of a child having a congenital cardiac malformation range from 2.5%-18% depending on the condition. A fetal echo, which is an ultrasound-based test, would be recommended to assess the fetus’ heart in mid-pregnancy.
This risk could be up to 50% if the mom has a condition such as DiGeorge syndrome (22q11 deletion), Marfan syndrome, familial hypertrophic cardiomyopathy, or the vascular form of Ehlers-Danlos syndrome. If you recognize any of these conditions as being present in a first-degree family member, make sure you assess your own risk.
Risks in delivery and postpartum
Planning ahead helps for those with pre-existing heart conditions.
Labor and delivery
Maternal heart disease is an important factor when planning for labor and delivery as well. The specific type of heart problem will determine whether routine delivery planning can be anticipated (possibly with increased monitoring and expert anesthesia care) or if cesarean section delivery is indicated to avoid the hemodynamic changes involved with labor.
New maternal heart problems
Some women, even those with no known heart disease, develop a condition called peripartum cardiomyopathy during the third trimester or during the postpartum period. This is more common in women who have preexisting cardiovascular disease. This is a rare, serious form of heart failure in which the chambers of the heart become enlarged and the muscle weakens.
The early signs are similar to some common benign symptoms of pregnancy, such as shortness of breath or fluid retention in the legs and feet. This can resolve over time and return to almost baseline level, but if it does not and the “squeeze” or ejection fraction of the heart remains poor, a future pregnancy would not be recommended.
Do you have heart disease symptoms?
Health care providers use classification systems to assess your risk of heart problems before, during, and after pregnancy to plan your care. One of the most common systems is the New York Heart Association Functional Classification. Here’s how it works:
- Class 1: No limitation of physical activity. You can go about daily life with no symptoms of fatigue or shortness of breath.
- Class 2: Slight limitation of physical activity. You feel comfortable at rest but might feel winded while walking up the stairs or fatigued after a brisk walk.
- Class 3: Marked limitation of physical activity. You feel comfortable at rest but have noticeable symptoms during ordinary activities such as housework or walking across a parking lot to your car.
- Class 4: Symptoms of heart failure at rest. You feel near-constant fatigue, extreme shortness of breath, or disruptive palpitations that cause discomfort even when you’re sitting or lying down.
If you think you might fall into any of the categories above Class 1, talk with your health care provider about your symptoms before you pursue pregnancy.
Talk with a doctor about your heart health risks
Several factors can increase your risk of cardiovascular problems while you’re pregnant:
- Becoming pregnant at age 40 or later
- Black or Asian American ethnicity
- Obesity
- Diabetes
- Poor physical fitness or a sedentary lifestyle
- Limited access to health care
If you identify with any of these categories, talk with a health care provider before considering pregnancy about additional tests, exams, or visits you may need to reduce your risks. Limited health care access is strongly associated with adverse outcomes; community resources may be available to help with barriers to care, such as transportation, childcare, and financial support to cover costs of health care.
If you have a heart condition and want to have a baby, see a health care provider for preconception counseling. The goal of this appointment is to talk through ways to optimize your heart health, review your medications and possible risks associated with carrying a pregnancy, and discuss other factors that influence your well-being, such as co-existing conditions that could include diabetes or high blood pressure. If there is any concern for some of the genetic conditions mentioned earlier, a preconception visit with a genetic counselor should also be part of your pre-pregnancy planning.
In some cases, your specialist team can recommend effective birth control options that take into account your underlying condition and, if desired, discuss alternate routes to biological parenthood, such as gestational surrogacy.
When you live with heart disease, there are some things you can’t change. However, you can actively participate in the management of your condition. Whether you have a heart condition or are at risk for one, working with a team of high-risk pregnancy specialists can give you the information and confidence you need to make informed decisions about your care.
Related reading:
Pregnancy can predict future heart health: Tips to shape your destiny
To make an appointment with a high-risk pregnancy expert, call 214-645-3838 or request an appointment online.
