How to monitor blood pressure in pregnancy?

Question

Hello doctor,

I am 26 weeks pregnant. My blood pressure has generally been in the normal range, usually between 120 and 129 mmHg. I had a midwife appointment a few days ago where my blood pressure was 142 mmHg and 143 mmHg (twice on one arm), and then 133 mmHg on the other arm. I was not nervous at the time.

Previously, I was being monitored in the hospital for another issue, and my blood pressure was checked regularly as part of routine care, almost every 24 hours, and it was normal. After returning home, I checked again and got a reading of 129 mmHg.

Because I was unsure, I visited a pharmacy the same day, and the readings were 123 mmHg, 125 mmHg, and 137 mmHg, eventually going up to 141 mmHg. I believe 141 mmHg was the second reading. I had walked to the pharmacy and was a bit out of breath at the time, which I felt could have influenced the result.

A couple of days later, I visited two more pharmacies. One used a wrist BP monitor, and the readings were 125 mmHg and 128 mmHg, which were both normal. The pharmacist mentioned the wrist monitor was more reliable than their arm monitor, which had previously shown a reading of 152 mmHg, something they believed was not accurate.

Later that evening, I visited another pharmacy, and my readings were 124 mmHg and 120 mmHg. To cross-check, I used a home blood pressure monitor we have had for a couple of years. It showed 129/80 mmHg. I do not know the brand, but it has been in the house for a while and has worked well in the past.

Then, I purchased a new BP machine that is validated for use during pregnancy, and I have been using that for recent measurements. It consistently gives readings under 120 mmHg, typically around 110 mmHg to 115 mmHg.

I also used another newer BP monitor for comparison, and that gave similar readings to the first one. This consistency makes me think these machines are reliable, but I am still confused. Which machine should I rely on?

I am also concerned about the variability in readings and whether any of these readings indicate high blood pressure. My pulse, as shown on the home monitors, is under 100 bpm, but it tends to be higher on other machines. I checked using an oximeter, too, and it shows a pulse under 100 bpm.

This situation is becoming very stressful. The midwife advised me to monitor at home, but the variations are making me anxious. I have never had this issue before. I hope you can help me understand what is going on, doctor, so I can feel a bit more reassured.

Kindly help.

Thank you.

Answer 1

Hello,

Welcome to icliniq.com.

I have read your query and understand your concern.

Blood pressure values above 140 mmHg (systolic) during pregnancy can be considered high and need proper evaluation. If left unmanaged, elevated BP can lead to complications.

It is essential first to ensure that your blood pressure is being measured accurately. Here are some important steps to follow:

Measure your blood pressure in a calm, quiet environment when you are relaxed.
Sit with your feet flat on the floor and your back supported.
Keep the arm used for measurement at heart level.
Avoid caffeine or tea for at least two hours before the reading.
Ensure your bladder is empty before measuring.
Take two readings daily, ideally at the same time each day.

For a diagnosis of hypertension, consistently elevated readings taken at least six hours apart using a reliable arm-based BP (blood pressure) monitor are necessary. Arm monitors are typically more accurate than wrist monitors and are preferred for clinical accuracy.

Since your recent readings from your new home BP monitors are consistent and within the normal range, it supports the reliability of those devices. The similarity of readings between the two different monitors at home, along with your pulse oximeter readings, adds to this reliability.

Higher readings in clinical settings could be due to white coat hypertension, a common phenomenon, especially during pregnancy, where anxiety or stress can cause elevated readings in medical environments.

Here is what I suggest:

Continue using one reliable arm-based BP monitor at home.
Monitor your blood pressure at least twice daily under ideal conditions, as outlined above.
Begin lifestyle changes such as reducing salt intake, eating a healthy diet (more vegetables and fruits, less red meat and processed food), avoiding excess weight gain, and limiting stress.
If consistently high readings occur despite lifestyle changes, consult your physician for further assessment and possible pregnancy-safe medication.

I hope that this answers your query.

Kindly follow up if you have more doubts.

Thank you.

Answer 2

Hello,

Welcome back to icliniq.com.

I read your query and understood your concern.

Yes, the home readings you are getting are likely reliable, especially since you are using a validated arm-based BP monitor and following the correct technique. Consistency in results across multiple readings and across more than one device further supports this reliability.

The difference in readings between home and clinical settings is likely due to white coat hypertension, a common condition where anxiety or stress during a medical appointment causes a temporary rise in blood pressure. This is well-documented and does not necessarily reflect your true resting blood pressure.

Since your home readings are consistently within the normal range and your pulse rate is also normal (as confirmed with an oximeter), there is no immediate cause for concern.

Just continue monitoring your BP at home as you have been doing and share the log with your healthcare provider. Based on your current home readings, there is no indication of high blood pressure at this point.

You are doing everything right, monitoring consistently, using reliable equipment, and seeking clarification when unsure.

I hope that this answers your query.

Kindly follow up if you have more doubts.

Thank you.