Table 3 Examples of text messages developed within each category

Congratulating for taking part

Hi [Firstname]. It’s great that you have signed up to BUMP. Taking your readings at home is an excellent way to learn more about your BP – you can also track it over time using the website or the app.

Health benefits of self-monitoring

Hi [Firstname]. Some women find that taking their own BP helps them to notice changes more quickly than they would normally. Log in now or text to send your reading.

Reassurance about the safety of taking part in the study

Hi [Firstname]. The best thing about checking your own BP is knowing when your BP is higher than normal. When this happens we will help you take action to manage it! Log in to find out more.

Risks associated with high BP/pre-eclampsia

Hi [Firstname]! Did you know that high BP affects about 1 in 10 women during pregnancy? Checking at home can help you quickly notice if your BP is too high!

Habit formation

Hi [Firstname]. A great way to get in the habit of taking your BP is to choose a time to suit you and setting an alarm on your phone as a reminder!

Keeping on track

Hi [Firstname]. It can be tricky to remember to take your BP! Using the BUMP app or website can help keep you on track and let you know what to do if your BP is too high! Why do not you log in today?

Information about BP variability/changes

Hi [Firstname]. Did you know that BP can change day-to-day and at different times of day? The great thing about checking at home is that we will have lots of readings to base any decisions about your care!

Risk in later pregnancy

Hi [Firstname]. BP often rises in the last few weeks of pregnancy – knowing what’s normal for you will help you notice if it starts to rise! You can see all your readings in the app or online.

Setbacks/missed readings (reassurance/what to do)

Hi [Firstname]. The odd missed reading does not matter. Do not worry, as long as you take a reading as soon as you can! Text or log in to send your reading today.

Disruption/changes to routine

Hi [Firstname]. Making a plan can help when it’s hard to remember to take your BP. Why not try keeping the monitor somewhere to remind you in the morning?