When pregnant women monitor their own blood pressure, care gets safer – but only if the system acts on the readings

Raised blood pressure affects one in ten pregnancies in England. Left undetected, it can lead to pre-eclampsia – a condition that threatens the life of both mother and baby. Clinic appointments catch some problems, but they are spaced weeks apart, and blood pressure can change between them. Women were already buying home monitors. The question was whether the health system could harness that instinct and make it work.

Our approach and partners

Researchers at the Nuffield Department of Primary Care Health Sciences spent twelve years building a programme of trials to answer that question – testing whether self-monitoring of blood pressure could improve the detection and management of high blood pressure (hypertension) in pregnancy and after childbirth.

The BUMP trials – the largest to date in the field – showed that self-monitoring during higher-risk or hypertensive pregnancy was feasible, acceptable to women and clinicians, safe, and no more expensive than usual care. Partners included Oxford University Hospitals NHS Foundation Trust, the Royal College of Obstetricians and Gynaecologists (RCOG), and Action on Pre-eclampsia.

When COVID-19 struck in March 2020, the team pivoted within weeks – adapting their intervention into the BPm-health app and making it available to the NHS free of charge. The RCOG published national guidelines for self-monitoring in pregnancy, drawing predominantly on this work. NHS England distributed 16,000 blood pressure monitors to maternity units.

Most recently, ARC funding supported the development of My Pregnancy Care – a digital intervention combining self-monitoring with remote management of medication and urinary protein testing.

What we found – and why it matters

1. Self-monitoring alone is not enough. The BUMP trials showed that while women could safely monitor their own blood pressure, self-monitoring did not improve detection of high blood pressure or blood pressure control when added to usual care.
2. Combining monitoring with active management changes the picture. The My Pregnancy Care feasibility study suggests that pairing self-monitoring with clinician-led remote adjustment of medication may help achieve healthier blood pressure during pregnancy.
3. The research shaped national and international policy. RCOG guidelines for self-monitoring in pregnancy were based predominantly on this programme's evidence. The work also informed US and French national clinical guidelines.
4. Inclusive recruitment is achievable with deliberate effort. The My Pregnancy Care study recruited over 80% of participants from disadvantaged or minoritised ethnic groups – demonstrating that representative research is possible when inclusion is designed in from the start.
5. The programme built research careers. ARC OxTV funding supported several midwives to develop as researchers, including one who completed a PhD, another who is now undertaking an NIHR doctoral award, and a third who received a pre-doctoral fellowship.

The postpartum arm of this work also showed lasting benefits. The POP-HT trial, originally ARC-funded, demonstrated long-term blood pressure control and cardiac benefits from self-management after hypertensive pregnancy. The SNAP-2 postpartum trial was nominated for the Transformative Innovation Award at the inaugural Black Maternal Health Awards 2025.

What this means

Self-monitoring is already widespread in maternity care – the pandemic accelerated its adoption across England. But adoption is not the same as effective use. Giving women a blood pressure cuff without optimising how clinicians respond to the readings leaves a critical gap. The tools exist; what needs to change is how the system acts on them.

For women from communities that experience the worst maternal outcomes, combining self-monitoring with active remote management offers a route to safer pregnancies with fewer unnecessary hospital visits.

What needs to happen next

Commissioners and maternity services need to move beyond distributing monitors and invest in the clinical pathways and digital infrastructure that allow readings to trigger timely action. This requires workforce capacity, clear protocols, and sustained attention to equity. Funders should recognise that inclusive trial design takes additional time and budget, and support it accordingly.

Lessons for future research

This programme's pandemic experience offers a broader lesson: established research relationships and infrastructure made rapid implementation possible. The team moved from evidence to national guidelines, a free app, and 16,000 distributed monitors within weeks – because the groundwork was already in place. The same principle applies to equity: the My Pregnancy Care study's success in reaching disadvantaged and minoritised communities reflected strategies built in from conception, not bolted on afterwards. Both require sustained investment – in infrastructure, in time, and in relationships.