Is an Increased Heart Rate in Pregnancy Early On Normal?
Due to the extra effort required to support a developing fetus in early pregnancy, the mother’s heart rate typically increases in the first trimester as blood pressure decreases. Although a heart rate increase in pregnancy is expected, and most women barely notice the difference, the extra stress on the heart can reveal underlying heart conditions in some women.
Given that cardiovascular disease is one of the leading causes of maternal death, recognizing the signs of a heart condition during pregnancy early is vital for a healthy and safe delivery.
Keep reading to understand why the heart rate increases during pregnancy, what’s normal, what’s not, and when you should contact your healthcare provider.
Why Does the Heart Rate Increase During Early Pregnancy?
The normal heart rate for females who are not pregnant typically ranges from 60-100 beats per minute depending on whether they are resting, exercising, or stressed. In early pregnancy, typically 2-5 weeks, the mother’s blood volume increases by almost 30-50% to support her body, organs, and the fetus. [1]
Due to this increased blood volume, the heart rate also rises to pump it around the mother’s body and to the placenta for fetal development.
How Much Does the Heart Rate Increase in Early Pregnancy?
How much a woman’s heart rate rises during the first trimester of pregnancy typically depends on her pre-pregnancy heart rate. On average, studies have concluded that in early pregnancy the heart rate increases by approximately 10% or 7-8 beats per minute. [2]
However, based on a woman’s baseline heart rate before pregnancy, medical experts also highlight that some heart rates may increase at a lower rate and some higher.
Your healthcare provider will typically check your heart rate and blood pressure during each prenatal check-up to ensure it is within the normal range.
Does the Heart Rate Increase Throughout Pregnancy?
When researching pregnancy and increased heart rate early pregnancy showed the largest rise with an average heart rate of 79 beats per minute. The heart rate typically continues rising in the second trimester and is known to increase by 45% at 24 weeks.
It was also noted that the heart rate can increase by 15% in a twin pregnancy compared to a single pregnancy. [3]
For some, the heart rate continues to steadily rise as pregnancy progresses, culminating at an average of 87 beats per minute at week 40. However, after the second trimester, the heart rate was found to plateau in some women, while increasing or decreasing in others.
Researchers and healthcare providers attribute the differences in heart rate increases during pregnancy to pre-pregnancy heart rates. Checking heart rates and blood pressure during each prenatal check-up is therefore vital in understanding each woman’s cardiovascular health. [4]
Are Heart Palpitations Common in Pregnancy?
Described as a racing or pounding heart that feels like it’s beating too quickly, too slowly, or skips a beat - heart palpitations during pregnancy are common. [5] Heart palpitations are generally caused by the increased volume of blood in the body during pregnancy and the heart working harder to pump it where it needs to be.
Although heart palpitations can feel strange and alarming, they are usually harmless during pregnancy and subside after childbirth. That said, pregnant women experiencing palpitations with chest pains, dizziness, or trouble breathing are advised to contact their healthcare provider immediately.
Why Abnormal Heart Rates Occur During Pregnancy?
Besides heart palpitations which are common during pregnancy, some women find that they don’t fit into the ‘normal’ range of heart beats per minute while expecting.
Common causes of an abnormal heart rate during pregnancy can include the following: [6]
- When an underlying and undiagnosed heart condition before pregnancy becomes more apparent during pregnancy
- Exercising regularly before pregnancy and continuing during pregnancy can mean the heart rate is typically lower
- The heart rate may have been high pre-pregnancy and the added effort required from the heart during pregnancy highlighted it
- Anxiety or stress can increase the heartbeat and stressing about an increased heart rate can exacerbate anxiety making the heartbeat even faster
If you are pregnant and experience a resting heart rate of 100 beats per minute, blurred vision, chest pain, dizziness, lightheadedness, extreme tiredness, or shortness of breath, contact your doctor immediately.
How to Keep Your Heart Rate Healthy During Pregnancy?
To optimize your cardiovascular health and keep the heart rate within an acceptable range, female health experts recommend exercising regularly, eating a well-balanced diet, keeping up with pre-natal exams, sleeping when tired, and managing anxiety with meditation or yoga. [7]
Conclusion
It’s normal for the heart rate to change during pregnancy, particularly early pregnancy, as the cardiovascular system works harder to pump extra blood to the uterus and growing baby. While some women barely notice these heart rate changes, others can find them worrying, and pre-existing heart conditions are also known to worsen during pregnancy.
If you’re pregnant and your elevated heart rate feels abnormal, or you feel chest pain, extreme fatigue, shortness of breath or dizziness, don’t hesitate to speak to your healthcare provider. Heart disease is a leading cause of maternal mortality when underlying conditions go undiagnosed.
Sources:
- Cleveland Clinic - Women and Heart Rate - https://my.clevelandclinic.org/health/articles/17644-women-and-heart-rate
- BMC Medicine - Trends of blood pressure and heart rate in normal pregnancies: a systematic review and meta-analysis - https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-019-1399-1
- National Library of Medicine - Serial study of factors influencing changes in cardiac output during human pregnancy - https://pubmed.ncbi.nlm.nih.gov/2705548/
- National Library of Medicine - Adaptation of the maternal heart in pregnancy - https://pubmed.ncbi.nlm.nih.gov/1467047/
- National Library of Medicine - Managing palpitations and arrhythmias during pregnancy - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2095764/
- Mayo Clinic - Heart Conditions and Pregnancy - Know the Risks - https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/pregnancy/art-20045977
- Mayo Clinic - Heart Conditions and Pregnancy - Know the Risks - https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/pregnancy/art-20045977
