Measuring blood pressure at home when pregnant or planning pregnancy: what to record, which symptoms matter, and how to share with your team
Blood pressure in pregnancy: how to monitor at home, what to record and share with your midwife, and which symptoms need urgent help.
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Maybe you have high blood pressure and want to become pregnant, or you are pregnant and your blood pressure has gone up. A calm plan helps: talk early with your midwife or doctor, measure correctly, and write down what you notice. You can keep readings on paper or in the blood pressure diary in Sam. Your partner can follow them through Friends & Family if you allow it.
If you have high blood pressure in pregnancy, home monitoring is sometimes part of care, and your midwife or doctor decides whether it fits you and how often. To measure, sit quietly for three to five minutes, keep your arm level with your heart, take two readings a day at the same times, and write them in a log.
This is general information, not medical advice, and it does not replace your midwife, doctor or obstetrician. A reading you take at home is not a diagnosis. What a value means for you, and how often you should measure, is decided by your care team.
What kinds of high blood pressure affect pregnancy?
Three terms come up. Chronic hypertension is high blood pressure you had before pregnancy, or that starts before 20 weeks. ACOG says gestational hypertension appears for the first time after 20 weeks and usually goes away after the birth. In pre-eclampsia, high blood pressure after 20 weeks is joined by other signs, such as protein in the urine or changes in blood tests.
Pre-eclampsia is common but usually mild. The Royal College of Obstetricians and Gynaecologists says it affects up to 5 in 100 women during their first pregnancy, and less than 2 in 100 during a second pregnancy. It can still be serious, so the checks matter.
High blood pressure often causes no symptoms, and pre-eclampsia can grow quietly. That is why your blood pressure is measured at every antenatal visit.
What should you do about high blood pressure when planning a pregnancy?
Talk with your care team when you start planning, not only after a positive test. Do not stop or lower your blood pressure medicine on your own. NICE says that if you take an ACE inhibitor or an angiotensin receptor blocker, there is an increased risk of problems if you keep taking it during pregnancy. Discuss alternatives when you plan a pregnancy. Your doctor decides which medicine fits you, and you keep taking what you agreed until then. If you take one of these and find out you are pregnant, contact your doctor straight away.
ACOG says that if you have high blood pressure and want to become pregnant, see your doctor for a check-up. You may have tests to see how your heart and kidneys are working, and your medicines may be reviewed. You should also talk about the signs of pre-eclampsia.
Questions you can take to the appointment:
- Is my current medicine suitable if I become pregnant, and what changes before then?
- Was a possible cause of my high blood pressure checked?
- Which blood pressure target applies to me?
- Which monitor is suitable, and is it validated for pregnancy?
- How often should I measure at home, and what do I record?
- Which symptoms should I report right away, and whom do I call outside opening hours?
Why your blood pressure is checked at every antenatal visit
Your blood pressure is measured at every antenatal visit. ACOG says your obstetrician should check it each time. Pre-eclampsia is most likely from 20 weeks onwards, but it can appear at any point, and sometimes in the days or weeks after the birth.
Because high blood pressure rarely causes symptoms you can feel, regular checks are how a problem is noticed. The checks are standard antenatal care, not a home task that replaces them.
When home monitoring helps, and which device to use
Home monitoring is sometimes part of care when you have high blood pressure in pregnancy. ACOG notes that if you have gestational hypertension or pre-eclampsia without severe features, you may stay at home with close monitoring. That can include measuring your blood pressure at home. It also says you may measure at home for one to two weeks after the birth. Your midwife or doctor decides whether home monitoring fits you, and how often.
For a device, the Preeclampsia Foundation recommends an arm or wrist cuff, not a finger monitor, and suggests asking your provider which device they trust. Not every monitor is validated for pregnancy, so check with your team rather than buying on impulse. Your care team tells you which device suits your pregnancy.
How to measure correctly and what to write down
The Preeclampsia Foundation describes the technique for home readings:
- Go to the toilet first, and sit quietly for three to five minutes.
- For 30 minutes before, avoid smoking, food, caffeine, exercise and taking your medicine (time the reading around your dose; never skip a dose for it).
- Sit with your arm propped level with your heart, feet flat on the floor, legs uncrossed. Do not talk while it measures.
- Take readings twice a day, at the same times and in the same position, and keep a log.
The Foundation also publishes home thresholds for when to call your provider, but these are US figures and not a target set for your own pregnancy. Ask your team which readings should make you call, and write the answer at the top of your log.
For what you write, one line per reading is enough:
| Date and time | Seated 5 minutes | Reading 1 and 2 | Symptoms today | Medicine as agreed | Note |
|---|---|---|---|---|---|
| Monday 7:30 | yes or no | both values | headache, flashing, rib pain, swelling | yes or no | Sleep, stress, anything unusual |
The symptoms column matters most for the conversation. You enter medicine only as yes or no, without a dose. Note the date of your next visit and its usual checks: blood pressure, weight and urine. For more on recording a series of readings, see blood pressure log: print or app.
In Sam's high blood pressure diary you enter the values, pulse and a short note with date and time, and readings from a monitor that writes to Apple Health can land there too. The doctor report (PDF) brings together the period you choose. You add only what you know yourself.
Which symptoms mean you should call right away
The NHS and NICE ask you to get help immediately during pregnancy if you have:
- a severe headache that does not go away,
- vision problems, such as blurring or flashing lights,
- severe pain just below the ribs,
- sudden swelling of the face, hands or feet,
- vomiting, or feeling very unwell,
- difficulty breathing (listed by ACOG, not by the NHS or NICE).
Tell your midwife or doctor right away, even if your measured blood pressure looks fine. Pre-eclampsia can develop quietly, which is why antenatal visits count even when you feel well. Symptoms also count even when your home reading is normal.
For a seizure, severe breathing trouble, confusion, or suddenly very severe symptoms, call your local emergency number (112 in the EU, 999 in the UK, 911 in the US), and call if you are ever in doubt. The NHS says to get urgent medical help right away if you are pregnant and have symptoms of pre-eclampsia: in the UK, call your maternity unit if you have the number, or NHS 111 if you have recently given birth or cannot reach it.
How do you share your readings with your partner and midwife?
Your partner can follow your blood pressure readings in Sam through Friends & Family. You choose the person and the area you share. They see it read-only, for that person, and until you stop the share. They need their own Sam account, see a snapshot your app refreshes, and receive no alerts about your values. The doctor report (PDF) is not part of that share, but you bring it to your appointment.
For your midwife or doctor you bring the log on paper or the doctor report as a PDF. The decision about your care stays with your care team.
Keep your blood pressure log in Sam for your maternity visits
You go to your antenatal visit with a readable series of readings instead of trying to recall them. The high blood pressure program in Sam is a diary with a doctor report, so readings, pulse and a short note sit together with a date and time.
- Instead of loose paper: you enter the values, and readings from a monitor that writes to Apple Health land there too.
- Instead of photos of the display: the doctor report (PDF) brings together the period you choose to show or print.
- Instead of calls in the evening: your partner reads along through Friends & Family, read-only and revocable at any time.
Sam does not measure blood pressure and does not replace your antenatal care. The categories Sam shows with averages follow general adult ranges, not pregnancy thresholds.
Try Sam HealthSam is a wellness companion, not a medical device. The app does not diagnose, treat, cure or prevent any condition or health state. Always consult qualified professionals for medical decisions.
Related reading
- High blood pressure diagnosis: what now
- Living with high blood pressure: daily readings
- How often to measure blood pressure
- Doctor visit checklist for a chronic condition
- High Blood Pressure at 30: Causes and Work-up
Sources
Updated: October 2026
- NHS: Pre-eclampsia (page last reviewed 23 March 2026)
- NICE: Hypertension in pregnancy: diagnosis and management (NG133) (published 25 June 2019, updated 17 April 2023)
- ACOG: Preeclampsia and High Blood Pressure During Pregnancy (FAQ034) (last reviewed April 2025)
- Preeclampsia Foundation: Signs and Symptoms (updated August 2025) and Blood Pressure: Check. Know. Share. (updated March 2025)
- Royal College of Obstetricians and Gynaecologists: Pre-eclampsia (last updated May 2026)
More on High Blood Pressure
Frequently Asked Questions
Can I stop my blood pressure tablets if I want to get pregnant?+
No, and not on your own. ACOG says not to stop any medicine without talking with your doctor, and NICE says to discuss alternatives to ACE inhibitors and ARBs when you plan a pregnancy. Which plan fits you is for your doctor to decide.
Do I need blood tests before pregnancy if I have high blood pressure?+
Sometimes. ACOG says your doctor may test how your heart and kidneys are working and review your medicines to see whether you need safer options during pregnancy. You should also learn the signs of pre-eclampsia, and your doctor decides what applies to you.
When should I measure my blood pressure at home?+
Follow your midwife or doctor. The Preeclampsia Foundation advises taking readings at the same time each day, in the same position, and sharing the log at each visit. Your care team sets how often you measure during pregnancy.
Which blood pressure monitor should I use?+
The Preeclampsia Foundation recommends an arm or wrist cuff, not a finger monitor, and suggests asking your provider which device they trust. It keeps a list of validated devices. Your midwife or doctor decides which monitor fits your pregnancy.
Which symptoms should I report right away?+
The NHS and NICE list a severe headache that does not go away, vision problems such as blurring or flashing lights, pain below the ribs, sudden swelling of the face, hands or feet, and vomiting. ACOG also lists difficulty breathing. Tell your midwife or doctor immediately, even if your measured blood pressure looks fine.
When do I call an emergency number during pregnancy?+
Call your local emergency number (112 in the EU, 999 in the UK, 911 in the US) if you have a seizure, severe breathing trouble, confusion, or suddenly very severe symptoms, and if you are ever in doubt. The NHS says to get urgent medical help right away if you are pregnant and have symptoms of pre-eclampsia.
Why is my blood pressure checked at every antenatal visit?+
High blood pressure usually causes no symptoms, and pre-eclampsia can develop quietly, which is why regular checks matter. ACOG says your obstetrician should check your blood pressure at each prenatal visit. The checks are part of antenatal care, not a replacement for it.