SELF-MONITORING OF BLOOD PRESSURE IN WOMEN WITH PREGNANCY HYPERTENSION: THE BUMP2 MULTICENTRE RANDOMISED CONTROLLED TRIAL

Abstract

Objective: Self-monitoring of blood pressure (BP), in conjunction with co-interventions, is associated with clinically significant BP reduction in the general adult population. No adequately powered trials have been conducted in women with pregnancy hypertension. The BUMP2 trial aimed to evaluate whether BP self-monitoring in women with pregnancy hypertension improved BP control. Design and method: This multicentre, non-masked, randomised controlled trial recruited pregnant women with chronic or gestational hypertension up to 37 weeks’ gestation. Participating women were randomised to either BP self-monitoring with telemonitoring and usual care or usual care alone. An app provided real time feedback advising women of appropriate actions to take at each blood pressure threshold. The primary outcome was mean systolic BP between baseline and delivery recorded by a healthcare professional. Secondary outcomes included maternal and perinatal outcomes, quality of life, and adverse maternal and fetal events. A sample size of 512 (256/group) at 90% power was required to detect a 5 mm Hg difference in systolic BP between groups (SD 16 mmHg), assuming 15% attrition, subsequently inflated to allow for analysis by hypertension type. Trial Registration: NCT03334149 Results: 850 women (454 with chronic hypertension (CH) and 396 with gestational hypertension (GH)) were randomised to either BP self-monitoring (CH n = 233; GH n = 197) or usual care (CH n = 221; GH n = 199). Primary outcome data were available from 821 (97%) women. Baseline characteristics were similar. Mean systolic BP between randomisation and delivery was not significantly different in women with chronic hypertension between self-monitoring (mean 133.8 (SD 10.3) mmHg) and usual care (133.6 (11.1) mmHg) groups; mean difference 0.03 (-1.73 to 1.79), p = 0.97 or in women with gestational hypertension (137.6 (12.1) mmHg vs. 137.2 (10.8) mmHg; mean difference -0.03 (-2.29 to 2.24), p = 0.98. There were no differences in other maternal and fetal outcomes or in Serious Adverse Events. Conclusions: BP self-monitoring in women with pregnancy hypertension does not improve BP control, but appears to be safe when used alongside usual care. Further work will elucidate whether empowering some women with BP self-monitoring may alter behaviour of clinicians or women in initiating or titrating antihypertensive medications.