Self-monitoring of blood pressure among women with hypertensive disorders of pregnancy: a systematic review

BACKGROUND: The World Health Organization (WHO) recommends self-monitoring of blood pressure (SMBP) for hypertension management. In addition, during the COVID-19 response, WHO guidance also recommends SMBP supported by health workers although more evidence is needed on whether SMBP of pregnant individuals with hypertension (gestational hypertension, chronic hypertension, or pre-eclampsia) may assist in early detection of pre-eclampsia, increase end-user autonomy and empowerment, and reduce health system burden. To expand the evidence base for WHO guideline on self-care interventions, we conducted a systematic review of SMBP during pregnancy on maternal and neonatal outcomes. METHODS: We searched for publications that compared SMBP with clinic-based monitoring during antenatal care. We included studies measuring any of the following outcomes: maternal mortality, pre-eclampsia, long-term risk and complications, autonomy, HELLP syndrome, C-section, antenatal hospital admission, adverse pregnancy outcomes, device-related issues, follow-up care with appropriate management, mental health and well-being, social harms, stillbirth or perinatal death, birthweight/size for gestational age, and Apgar score. After abstract screening and full-text review, we extracted data using standardized forms and summarized findings. We also reviewed studies assessing values and preferences as well as costs of SMBP. RESULTS: We identified 6 studies meeting inclusion criteria for the effectiveness of SMBP, 6 studies on values and preferences, and 1 study on costs. All were from high-income countries. Overall, when comparing SMBP with clinic-monitoring, there was no difference in the risks for most of the outcomes for which data were available, though there was some evidence of increased risk of C-section among pregnant women with chronic hypertension. Most end-users and providers supported SMBP, motivated by ease of use, convenience, self-empowerment and reduced anxiety. One study found SMBP would lower health sector costs. CONCLUSION: Limited evidence suggests that SMBP during pregnancy is feasible and acceptable, and generally associated with maternal and neonatal health outcomes similar to clinic-based monitoring. However, more research is needed in resource-limited settings. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42021233839.