Pregnancy is one of the most remarkable things the human body does. To support a growing baby, your heart and circulation adapt in ways that are genuinely extraordinary, and for the vast majority of women, pregnancy is a safe and healthy experience.

That said, the heart is working harder than usual, and it helps to understand what is normal, what is worth mentioning, and, in the rare cases where something does need attention, what good care looks like. This article is designed to give you that picture clearly and honestly, without causing unnecessary alarm.

What happens to your heart during pregnancy?

From the earliest weeks of pregnancy, your cardiovascular system begins to adapt. Blood volume increases by up to 50% to support the placenta and baby. Your heart beats faster, typically 10 to 20 beats per minute more than usual. And the total output of blood your heart pumps each minute increases significantly, often by 30 to 50%.

Blood pressure tends to fall slightly in the first and second trimester as blood vessels relax and widen, before gradually returning toward your normal level in the third trimester. These are not signs of anything going wrong, they are the body doing exactly what it is supposed to do.

What this means practically is that your heart is doing more work. And like any system under increased load, it can produce symptoms that, understandably, feel concerning, even when they are entirely expected.

Symptoms that are usually a normal part of pregnancy

Many of the cardiovascular symptoms women notice during pregnancy are simply the body adjusting to its new demands. They are worth knowing about so they do not come as a surprise.

In my experience, the women who feel most at ease during pregnancy are those who know what to expect from their body, and who feel confident enough to speak up when something doesn’t feel right.

These symptoms are common and usually reassuring when they occur in isolation and do not dramatically worsen. If any of them feel sudden, severe, or out of proportion, they are always worth mentioning to your midwife or doctor, not because they are likely to be serious, but because it is always better to be certain.

Blood pressure in pregnancy

Blood pressure monitoring is one of the most important aspects of antenatal care, and for good reason. While mild falls in blood pressure early in pregnancy are normal, a significant rise, particularly in the second half of pregnancy, needs attention.

Gestational hypertension

Some women develop high blood pressure after 20 weeks of pregnancy without any other features. This is called gestational hypertension. It often resolves after delivery, but it does require monitoring and sometimes medication to keep blood pressure within a safe range for both mother and baby.

Pre-eclampsia

Pre-eclampsia is a more significant condition that combines high blood pressure with signs that other organs, typically the kidneys or liver, are under stress. It affects around 2–8% of pregnancies. Symptoms can include persistent headache, visual changes, upper abdominal pain, and sudden worsening of swelling.

Pre-eclampsia is taken seriously because of its potential to progress, but it is also one of the most closely monitored conditions in obstetric care. Women who develop it are supported carefully, and the condition resolves after delivery. If you have risk factors such as a first pregnancy, multiple pregnancy, obesity, diabetes, or a family history of pre-eclampsia, your team will be watching closely from the outset.

Heart rhythm changes in pregnancy

Palpitations are among the most common cardiac symptoms reported during pregnancy, and in the vast majority of cases they are entirely benign. The combination of a faster heart rate, higher blood volume, and the hormonal environment of pregnancy can make extra heartbeats, known as ectopic beats, more noticeable than usual.

Most of the time, these are harmless. They do not require treatment and typically settle after delivery. However, if palpitations are frequent, prolonged, associated with dizziness or fainting, or feel like a sustained rapid or irregular rhythm, they are worth reporting. An ECG is quick, painless, and safe in pregnancy, and can provide important reassurance or identify whether any further assessment is needed.

Some women with pre-existing heart rhythm conditions, such as supraventricular tachycardia (SVT), find that episodes become more frequent during pregnancy. This is manageable with appropriate monitoring and, where needed, treatment that is safe for the baby.

Peripartum cardiomyopathy

Peripartum cardiomyopathy is a rare condition in which the heart muscle becomes weakened in the final month of pregnancy or in the months following delivery. It is uncommon, affecting approximately 1 in 1,000 to 1 in 4,000 pregnancies, but it is important to be aware of.

The symptoms can overlap with normal pregnancy experiences, breathlessness, fatigue, and swelling, which is why any significant or rapidly worsening symptoms in late pregnancy or after delivery deserve prompt attention. When recognised early, the outlook is genuinely encouraging. Most women with peripartum cardiomyopathy recover well with appropriate treatment, and many regain normal heart function within months.

Risk factors include older maternal age, multiple pregnancy, pre-eclampsia, and African heritage. If you develop new and significant breathlessness, difficulty lying flat, or swelling that seems out of proportion in the weeks around delivery, mention it to your doctor promptly, not because it is likely to be serious, but because early assessment makes a real difference.

SCAD, Spontaneous Coronary Artery Dissection

Spontaneous coronary artery dissection, or SCAD, is a rare but important cause of heart attack in young women, and it has a particular association with pregnancy and the postpartum period. It occurs when a small tear develops in the wall of a coronary artery, disrupting blood flow to part of the heart muscle.

SCAD can feel like a classic heart attack, chest pain, breathlessness, and sometimes pain radiating to the arm or jaw. In the context of a recently pregnant or postpartum woman, these symptoms should always be taken seriously and assessed urgently. The good news is that the majority of women with SCAD recover well, and with the right specialist support, outcomes are positive.

We have a dedicated article on SCAD on this site if you would like to understand more about this condition.

Pre-existing heart conditions and pregnancy

Women with known heart conditions, including congenital heart disease, valve disease, or cardiomyopathy, can and do have successful pregnancies. The key is planning ahead with a specialist team who can assess how pregnancy is likely to affect your individual situation and put appropriate monitoring in place from early on.

This kind of joint care, between your cardiologist and your obstetrician, makes an enormous difference. It allows potential issues to be anticipated rather than reacted to, and ensures that any medications you are on are reviewed for safety in pregnancy well in advance.

If you have a heart condition and are thinking about starting a family, a preconception appointment with your cardiologist is one of the most valuable investments you can make.

Investigations that are safe in pregnancy

If your doctor or midwife wants to investigate a cardiac symptom during pregnancy, there are several tests that are completely safe and commonly used.

An ECG is painless and safe at any stage of pregnancy. An echocardiogram uses ultrasound, the same technology used to image your baby, and carries no radiation risk whatsoever. Blood tests, including markers of heart stress, can also be checked safely if there is clinical concern. Your team will only request investigations when they are genuinely needed, and they are experienced in interpreting results in the context of pregnancy’s normal physiological changes.

Medications in pregnancy

Some cardiac medications are safe to continue during pregnancy, others need to be adjusted, and a small number should be avoided. This is an area where the guidance is specific to each person and each condition, a medication that is appropriate for one woman may not be right for another.

If you are on cardiac medication and become pregnant, or are planning a pregnancy, speak with your cardiologist as early as possible. Do not stop any medication without guidance, as this can sometimes carry its own risks. The goal is always to find the approach that best protects both you and your baby.

After pregnancy, looking after your heart long-term

The period after delivery is an important one for heart health monitoring. Peripartum cardiomyopathy, SCAD, and postpartum pre-eclampsia can all emerge or continue in the weeks after birth, so paying attention to new symptoms after delivery matters just as much as during pregnancy.

Beyond the immediate postpartum period, there is growing evidence that complications in pregnancy, particularly pre-eclampsia, gestational diabetes, and preterm delivery, are associated with a modestly increased risk of cardiovascular disease later in life. This does not mean that heart disease is inevitable; it means that your pregnancy history is a useful part of your overall health picture.

When you see your GP or cardiologist in future years, mention any significant pregnancy complications. It allows your longer-term cardiovascular risk to be assessed appropriately and helps ensure that any preventive measures, lifestyle, blood pressure monitoring, cholesterol checks, are put in place at the right time.

Questions to Ask Your Midwife or Cardiologist

Going into appointments prepared helps you get the most from the time you have. Here are some questions worth raising:

Conclusion

Pregnancy is a time of extraordinary change for the heart and circulation, and for the vast majority of women, those changes unfold safely, supported by a body that is remarkably well designed for the task. Most cardiac symptoms during pregnancy are a normal part of that adaptation, not a warning sign.

Where conditions do arise, whether blood pressure changes, rhythm disturbances, or the rarer but important conditions like peripartum cardiomyopathy or SCAD, the outcomes with good care are genuinely encouraging. Awareness is not the same as anxiety; knowing what to look for means that if something does need attention, it gets it promptly.

Your maternity and cardiac teams are there to support you at every stage. Trust your instincts, speak up when something feels different, and know that asking questions is always the right thing to do.