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Serving the Susquehanna Region

UPMC Provider: Pregnancy’s Effects on the Heart

by Darcie Desiderio, DNP, CRNP

A woman’s body goes through many changes during pregnancy. Many of them are obvious like the belly bump, but some are more subtle or hidden like how pregnancy affects the heart and blood vessels. Due to these changes, some women may develop a new heart condition during pregnancy, or an existing cardiac condition can worsen. So, when you’re pregnant, it’s important to know what to expect.

Typical Heart Changes

Your body undergoes many changes in a typical pregnancy as it prepares to create space and promote healthy growth of your child. Healthy changes of the heart and blood vessels, include:

  • A 40 – 50% increase in blood volume
  • The extra blood volume makes the heart work 30 to 40% harder 
  • Heart rate increases 10 to 15 beats per minute
  • Blood pressure decreases

These changes usually normalize when the baby is born. By three months postpartum, your cardiovascular system generally has snapped back to pre-pregnancy status.

Added Risks of Pregnancy

Pregnancy is a risk factor for the development of blood clots especially deep vein thrombosis (DVT). Pregnancy and delivery are independent risk factors for spontaneous tears in the aorta, however the presence of other conditions such as connective tissue diseases can compound the risk.  Additional pregnancy-induced complications include high blood pressure, pre-eclampsia, cardiomyopathy, heart failure, gestational diabetes, heart murmurs, and worsening valve problems. 

Peripartum cardiomyopathy, or PCM, is rare but can be a life-threatening heart condition which may develop either late in pregnancy or after delivery. It can be difficult to diagnose because the symptoms are similar to a normal pregnancy and include shortness of breath and swelling in the legs and feet.

Some conditions — like pre-eclampsia and gestational diabetes — resolve after childbirth. However, these conditions place women at an increased risk of heart disease in the future. 

Take a Heart Healthy Approach from the Start

During pregnancy, if you have a pre-existing heart condition you may be at increased risk for complications. It is important to monitor and treat any existing issues with your heart as well as seek care if new conditions arise. In addition, regular prenatal exams can sometimes uncover a previously undiagnosed heart issue. 

It is important to find a cardiac specialist you trust who will work with your OB-GYN before, during, and after your pregnancy to ensure the safety of you and your baby. Women with an underlying or known cardiac condition need to take special precautions before and during pregnancy. If new symptoms surface during pregnancy, your doctor needs to know. 

Following a healthy diet and staying active are the top two ways to protect your heart before and during pregnancy. You may have some limitations while you are pregnant, but it is important to stay active and take a few short walks every day.

Start your prevention efforts as soon as you decide to grow your family. Your OB/GYN or cardiologist can offer guidelines on diet and exercise throughout your pregnancy. Your lifestyle choices during pregnancy can protect your heart for years to come.

Learn more about Women's Heart & Vascular services at UPMC.