Paula Pinell-Salles, MD, FACC, specializes in general cardiology and vascular medicine and is a Co-Founder of Inova’s Women’s Heart Health program. She is board certified in cardiovascular disease. Dr. Pinell-Salles is a cardiologist in Virginia Heart’s Fairfax office.
For most women, pregnancy is marked by good health and the excitement of bringing a new life into the world. Still, it’s important to know about the impact of pregnancy on the heart and to be proactive in identifying potential health concerns early.
How Pregnancy Affects the Heart
Blood volume increases – In order to support blood flow to the placenta, blood volume increases by almost 40 percent and output of blood volume from your heart can increase 30 to 50 percent. Your arteries relax to accommodate this increased flow and volume. These changes can cause swelling in your legs.
Palpitations – Changing hormone levels can increase your resting heart rate by 10 to 25 percent. Some women experience increased fluttering from brief abnormal heart rhythms or extra heart beats called premature ventricular contractions (PVCs) or premature atrial contractions (PACs). While these can be uncomfortable, they are usually harmless.
Blood pressure changes – In most women, blood pressure decreases because of hormones and changes in blood flow. A small percentage of women develop hypertensive disorders of pregnancy, which can increase the risk to mother and baby if not managed.
Shortness of breath – By the third trimester, it is not unusual to experience shortness of breath. This is caused by hormones, your enlarging uterus, increased blood volume, and, sometimes, anemia.
If you are concerned about any of these symptoms, it is important to tell your medical provider. What’s normal in some women may represent a serious complication in others. Your doctor will monitor your symptoms, blood pressure and do further lab work. You will be referred to a specialist in cardio-obstetrics if it’s warranted.
Be Proactive Before and During Your Pregnancy
It’s important to take steps to maintain good health during your pregnancy and to understand your risks going into a pregnancy.
Consider these general health tips:
- Eat a healthy diet.
- Exercise, but avoid lifting heavy objects.
- If you smoke or vape, stop.
- Stop using recreational drugs and seek professional help right away for a substance use disorder that could harm your baby.
- Consult your medical provider before you get pregnant or early in your pregnancy if you have any of the preexisting conditions listed below.
Preexisting Conditions that May Affect Pregnancy
High Blood Pressure – Women with a history of hypertension are at elevated risk for preeclampsia, which can lead to serious complications for both you and your baby. Additionally, many commonly used blood pressure medications are not safe in pregnancy and will need to be transitioned – ideally before pregnancy.
Existing Heart Condition or Structural Heart Defects (e.g., cardiomyopathy, bicuspid aortic valve, Marfan’s syndrome) – These women should have baseline imaging and consult with their cardiologist regarding their risk and specifically how they will be monitored and followed if pregnant.
Chronic anticoagulant use – Clotting risk is generally higher in pregnancy. If you are on blood thinners for a prior mechanical valve replacement or history of blood clots, your doctor will need to adjust your blood thinner medication. For example, newer blood thinners are not safe in pregnancy. Coumadin and heparin alternatives (injectables and IV medicines) each have important pros and cons in different stages of pregnancy, which will guide your doctor’s recommendations.
Diabetes – Poor control of diabetes during pregnancy can cause serious complications for you and your baby. Women with diabetes are also at increased risk for hypertensive disorders of pregnancy and preeclampsia and should follow their blood pressure closely.
Maternal Age Over 35 – As women get older, they are more likely to have developed traditional heart risk factors like diabetes and high blood pressure and are, therefore, more likely to develop hypertensive disorders of pregnancy.
Ethnicity – Black and Asian women have an increased risk of developing complications, including preeclampsia.
After giving birth, women with some of these risk factors face a higher risk of cardiovascular disease for three to six months, so continued monitoring by your doctor in the “fourth trimester” is very important. In addition, those who experience health complications while pregnant are at higher risk for high blood pressure and heart disease long-term. Pregnancy provides an invaluable opportunity for these women to work with a doctor to set health targets and prevent these complications in the future.
The good news is that most pregnancies are uncomplicated, and many women with preexisting cardiovascular conditions can have a healthy pregnancy and give birth to a healthy baby.
During this special time in your life, remember to slow down, enjoy the pregnancy and stay in tune with your body.