Published: 03 May 2022
Self-monitoring of blood pressure during pregnancy does not help detect high blood pressure earlier, according to the results of a large new clinical trial. A second trial showed that self-monitoring also doesn’t help improve blood pressure control in women who already have high blood pressure or develop it during pregnancy.
However, the researchers commented that self-monitoring was shown to be safe and acceptable to women, and the results would help to shape future research to improve the health of women with high blood pressure during pregnancy.
The two studies, called BUMP1 and BUMP2, involved over 3000 participants and were published in the Journal of the American Medical Association. The studies were led by researchers from the University of Oxford and King’s College London, funded by NIHR Programme Grants for Applied Research.
Dr Katherine Tucker, lead author on the paper looking at early detection of high blood pressure and a Senior Researcher at the Nuffield Department of Primary Care Health Sciences, University of Oxford said: “Around one in ten people who are pregnant will have high blood pressure, also called hypertension. For around half of them this can develop into pre-eclampsia, a condition that puts both mother and baby at risk.
“We know that self-monitoring of blood pressure in the general population has been shown to improve the diagnosis and management of hypertension, however, prior to these studies, little was known about its usefulness in pregnancy.”
The BUMP1 and BUMP2 trials took place across 15 hospitals in England. In BUMP1, women who were identified as being at higher risk of pre-eclampsia were randomly assigned to two groups - one receiving normal NHS care and the other doing additional self-monitoring of their blood pressure. BUMP2 recruited women who had high blood pressure prior to becoming pregnant or who had already developed it during their pregnancy, and split them into the same two groups.
The trials found that self-monitoring made no difference to the timing of when high blood pressure was diagnosed, or to how well it was controlled during pregnancy.
Professor Lucy Chappell, Professor of Obstetrics at King’s College London, said: “We set up the BUMP trials to find out if home blood pressure monitoring might help early identification of hypertension in pregnancy, or the control of blood pressure for those with pregnancy hypertension. Importantly neither trial found any problem with self-monitoring, and there were high levels of acceptability.
“Further work will be needed to investigate if home readings can be used to support improvements in health outcomes for this group. In the meantime, women and pregnant people who wish to self-monitor can continue to do this and are advised to share their readings with their midwives/other clinicians. We would now like to consider how to develop the interventions further so that we can understand how we can improve health outcomes for women with pregnancy hypertension.”