Self-monitoring of blood pressure in women with higher risk pregnancies: the BUMP1 multicentre randomised controlled trial
Problem
Self-monitoring of blood pressure (BP) in the general adult population has been shown to support the diagnosis and management of hypertension. However, ew data are available for its use in antenatal care. The BUMP1 trial aimed to evaluate whether self-monitoring of BP during higher risk pregnancy improved the detection of pregnancy hypertension.
Approach
This multicentre, non-masked, randomised controlled trial recruited pregnant women at higher risk of pre-eclampsia at 20 weeks’ gestation (+/-4 weeks). Participating women were randomised to either BP self-monitoring with telemonitoring and usual care or to 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 the time to the first recorded raised BP taken by a healthcare professional. Secondary outcomes included maternal and perinatal outcomes, quality of life, and adverse maternal and fetal events. A sample size of 2262 (1131/group) at 90% power was required to detect hypertension 14 days earlier (SD 45 days), assuming 16% of the women would develop hypertension with 15% attrition.
Trial Registration: NCT03334149 (clinicaltrials.gov)
Findings
2441 women were randomised to either BP self-monitoring (n=1223) or usual care (n=1218). Primary outcome data were available from 2346 (96%) women. Baseline characteristics including age, parity and baseline blood pressure were similar. Hypertension was diagnosed in 15.5% of women. Time to detection of raised blood pressure was not significantly different between self-monitoring and usual care groups (mean 104 days vs 106 days in the usual care group) giving a difference in days of -1.6 (-8.1 to 4.9, p=0.6). There was no difference in incidence of severe hypertension (adjusted relative risk 1.2 (0.9 to 1.7), p=0.3), quality of life or other maternal and fetal outcomes. There were no significant differences in Serious Adverse Events.
Consequences
Self-monitoring of BP during higher risk pregnancy appears to be safe, but did not improve the detection of hypertension in women with higher risk of pre-eclampsia when used alongside usual care. Further work is required to assess the place of self-monitoring of blood pressure in place of usual antenatal care, for instance in remote consultations, and to assess self-management.