Understanding Blood Pressure in Pregnancy

Learn why monitoring blood pressure in pregnancy is vital and how to use our free tracker to spot trends worth raising with your midwife or doctor.

During your pregnancy, you’ll notice that your midwife or doctor checks your blood pressure at every single visit. It’s a quick, simple check, but it’s one of the most important parts of your antenatal care. These regular readings give your care team a clear picture of how your body is adapting to pregnancy and help them catch any potential issues early.

For most people, blood pressure stays within a healthy range throughout their pregnancy journey. However, for some, it can rise, which may be a sign of a condition that needs closer monitoring. Keeping track of your blood pressure readings between appointments can help you feel more informed and play an active role in your care. It transforms numbers on a screen into a meaningful story you can share with your care team.

This guide will walk you through why monitoring blood pressure in pregnancy is so vital, how to track your readings effectively, and when to reach out for professional advice. It’s all about empowering you with information, not causing worry.

Why this matters

Your blood pressure is the force of your blood pushing against the walls of your arteries as your heart pumps. It’s measured as two numbers:

Systolic pressure (the top number): The pressure when your heart beats.
Diastolic pressure (the bottom number): The pressure when your heart rests between beats.

A reading is written as systolic over diastolic, for example, 120/80 mmHg (millimetres of mercury).

During pregnancy, your body goes through incredible changes. You create more blood to support your growing baby and placenta, and your cardiovascular system works harder. In a healthy pregnancy, your blood vessels relax and widen to handle this extra volume, which often causes blood pressure to be a little lower in the first and second trimesters before returning to your pre-pregnancy baseline in the third.

However, sometimes this process doesn’t go as smoothly. When blood pressure rises above a certain threshold after 20 weeks of pregnancy, it’s known as gestational hypertension. While it can be managed, it requires careful monitoring because it can sometimes be a warning sign of a more serious condition called pre-eclampsia.

Understanding pre-eclampsia

Pre-eclampsia is a complex condition that typically occurs after 20 weeks of pregnancy and involves high blood pressure combined with other signs that your organs aren’t working as they should. These signs can include protein in your urine (detected by your midwife), severe headaches, vision problems, or pain just below your ribs.

The exact cause of pre-eclampsia is still being researched, but it’s thought to be related to the placenta not developing properly. It can affect both the birthing parent and the baby, restricting the baby's growth and, in serious cases, leading to complications. The good news is that with regular antenatal checks, it is usually picked up and managed early. This is why your team is so diligent about that blood pressure cuff at every visit. You can read more about what to expect from your appointments in our Guide to a Healthy Pregnancy.

Tracking your readings helps you and your team establish your personal baseline and spot any changes quickly. It puts you at the centre of your care, turning routine checks into a powerful tool for your health and your baby’s.

How the Pregnancy Blood Pressure Tracker works

The Pregnancy Blood Pressure Tracker is a simple, private space for you to log the readings taken at your appointments or at home. Think of it as your personal health diary, designed to complement the care you receive from your midwife or doctor—it does not replace it.

By keeping all your numbers in one place, you can:

See your trends: A single high reading can be caused by many things, like feeling rushed or anxious. A consistent upward trend over days or weeks is more meaningful, and our tracker’s chart makes this easy to see.
Feel more prepared for appointments: Instead of trying to remember past readings, you can simply show your log to your care provider. This helps them make a more thorough assessment. You can keep all your appointment details organised with our Antenatal Appointments Tracker.
Connect readings with how you feel: Our tracker has a notes section, so you can jot down if you had a headache or felt unusually swollen on a particular day. This context is incredibly valuable. For more detailed symptom logging, you can use the dedicated Pregnancy Symptom Tracker.

You can also use the Pregnancy Records tool to securely store photos of your official antenatal records, blood test results, and scan reports, keeping everything together in your private Pregnancy Hub Pro dashboard.

Step-by-step guide

Using the tracker is straightforward. Here’s how to get the most out of it.

Set up your tracker: Navigate to the Pregnancy Blood Pressure Tracker and enter your due date. This sets up your personal tracking timeline.
Decide on home monitoring (optional): Many people choose to monitor their blood pressure at home between visits. If you wish to do this, speak with your doctor, midwife or pharmacist about choosing an automated blood pressure machine with an upper-arm cuff that is validated for use in pregnancy. They can help you find a reliable device.
Learn to take an accurate reading: To get a reliable result, you need to be consistent. Avoid caffeine, smoking or exercise for 30 minutes before. Sit quietly for 5-10 minutes first. Sit in a chair that supports your back, with your feet flat on the floor and your arm resting on a table at heart level. Follow the instructions that came with your machine.
Enter your readings: In the tracker, tap ‘Add New Reading’. Enter the date, time, your systolic number (top), and diastolic number (bottom). Most machines also provide your heart rate (pulse), which you can add too.
Add important context: This is a crucial step. Use the ‘Notes’ field to add any relevant information. Did you have a headache? Were your feet more swollen than usual? Did you feel stressed or rushed? This context helps you and your care team interpret the numbers.
Record readings from your appointments: After each antenatal visit, add the blood pressure reading your midwife or doctor took. This builds a complete picture, combining professional checks with your home monitoring.
Review your chart: The tracker automatically plots your readings on a graph. This visual tool makes it easy to see your personal pattern over the weeks. Is it stable? Is there a gentle upward curve? This is the information that’s so useful to share.
Share your log at your next visit: Bring your phone or a printout of your log to your next appointment. Show your midwife or doctor your trends. This opens up a more detailed conversation about how you’re progressing and is a great way to feel like a team.

Common mistakes (and how to fix them)

Home monitoring is only useful when the readings are accurate. Here are some common pitfalls to avoid.

Mistake: Using a cuff that doesn’t fit

The problem: A cuff that is too small for your arm can give a falsely high reading, while a cuff that’s too large can give a falsely low one.
The fix: Before buying a machine, measure the circumference of your upper arm. Check that your measurement falls within the range listed for the cuff. Most standard cuffs fit a typical adult arm, but you may need to order a smaller or larger size separately.

Mistake: Taking your reading when you’re stressed or rushed

The problem: Pain, anxiety, and rushing around all cause a temporary spike in blood pressure. Measuring it at these times won’t reflect your true resting state.
The fix: Always rest for at least 5 minutes in a quiet, calm space before taking a reading. Sit comfortably and take a few slow, deep breaths to help you relax.

Mistake: Incorrect posture or arm position

The problem: If your arm is hanging down or held up too high, the reading will be inaccurate. Similarly, if you are slouched or have your legs crossed, it can affect the result.
The fix: Always sit in a supportive chair with your back straight and your feet flat on the floor. Rest your arm on a table or cushion so that the cuff is roughly at the same level as your heart.

Mistake: Measuring at inconsistent times

The problem: Your blood pressure naturally fluctuates throughout the day. Comparing a morning reading with an evening one might not give you a clear sense of your overall trend.
The fix: For the most consistent tracking, try to take your readings at the same time each day, for example, once in the morning and once in the evening. This creates a much more reliable pattern to follow.

Mistake: Focusing only on one high number

The problem: It’s easy to feel anxious about a single reading that seems high. However, a one-off result isn’t nearly as informative as a consistent pattern.
The fix: Log the reading and the context (e.g., “felt stressed,” “had an argument”). Take it again later after you’ve rested and calmed down. Focus on the trend over several days, which you can see on the tracker’s chart. This is the information your care team will find most helpful.

When to seek professional advice

Your antenatal care team is there to support you. You should never hesitate to contact your midwife, doctor, or maternity assessment unit if you are concerned about your blood pressure or your wellbeing. The tracker is for logging information, not for self-diagnosing.

Call your midwife, doctor or maternity hospital for advice if:

You get a blood pressure reading that is significantly higher than your usual baseline, even if you feel fine. Your care team will have told you what numbers they consider high for you.
You have a high reading that remains high when you check it again after a period of rest.
You have mild but persistent swelling in your hands, face or feet that is new for you.
You generally just don’t feel right.

Seek urgent medical attention by calling your maternity hospital or going to the nearest emergency department if you have any of the following symptoms, which can be signs of severe pre-eclampsia:

A severe headache that doesn’t go away with simple pain relief like paracetamol.
Problems with your vision, such as blurring, flashing lights or spots.
Severe pain just below your ribs.
Sudden and significant swelling of your face, hands or feet.
Vomiting.
Feeling very unwell.

Trust your instincts. It is always better to get checked out and be told that everything is fine than to wait at home and worry.

Try the free tracker

Take control of your health journey by keeping a simple, clear record of your blood pressure readings. Our tracker makes it easy to spot trends and have more informed conversations with your care team. It’s free to start and part of your complete pregnancy toolkit.

Start tracking your blood pressure now