Clinical scenario:
34-year-old female with no PMH, G1P0, at 20 weeks of gestation based on LMP, presented to the clinic for routine prenatal care. Patient reported that her sister developed preeclampsia during her pregnancy. The patient asked if she should monitor her blood pressure at home on a regular basis for early detection of gestational hypertension.
Clinical Question:
Does at-home blood pressure monitoring lead to early detection of gestational hypertension and better maternal outcomes?
Question Type:
□ Therapy/ Prevention □ Diagnosis □ Etiology □ Prognosis
□ Screening □ Prevalence □ Harms
PICO search terms:
| P | I | C | O |
| Women | At-home blood pressure monitor | Office blood pressure monitor | Early detection of gestational hypertension |
| Pregnant | Self-monitoring of blood pressure | Clinic blood pressure monitor | Early detection of preeclampsia |
| Home blood pressure monitor | Maternal outcomes |
Search strategy:
| Database | Filter | Terms Searched | Articles Returned |
| PubMed | Last 5 years English Clinical trial, meta-analysis, RCT, systemic review | Home blood pressure monitoring during pregnancy | 28 |
| Google scholar | Last 5 years English Systemic Review | Home vs. office blood pressure monitoring in pregnancy | 16700 |
| Cochrane Reviews | English Review articles Last 5 years | Self monitor of blood pressure during pregnancy | 3 |
I narrowed down the results the year of publication and by the type of articles first. For this clinical question, I’m evaluating the benefits of home blood pressure monitoring in pregnant patients. The best study would be systemic review or RTCs. To look for more recent studies, I filtered out the studies that were published more than 5 years ago. Next, I screened the title and abstract to look for the most relevant articles.
Results found:
Article 1
Article 2:
Article 3
| Citation: Kalafat, E., Benlioglu, C., Thilaganathan, B., & Khalil, A. (2020). Home blood pressure monitoring in the antenatal and postpartum period: A systematic review meta-analysis. Pregnancy hypertension, 19, 44–51. https://doi.org/10.1016/j.preghy.2019.12.001 |
| Type of Study: Systemic review and meta-analysis |
| Recent evidence suggests that home blood pressure monitoring (HBPM) is an effective way of managing women with hypertensive disorders of pregnancy (HDP) without increasing adverse outcomes. The aim of this systematic review and meta-analysis was to investigate the safety and efficacy of HBPM during pregnancy. Medline, EMBASE and the Cochrane library databases were searched electronically in November 2018. Studies were included from which data could be extracted on the pregnancy outcomes and included pregnancies with HDP or at increased risk of developing HDP. Data from nine studies were included in the meta-analysis. The use of HBPM during the antenatal period was associated with reduced risk of induction of labor (OR: 0.55, 95% CI: 0.36-0.82, 444 women, I2 = 0%), prenatal hospital admissions (OR: 0.31, 95% CI: 0.19-0.49, 416 women, I2 = 0%) and diagnosis of preeclampsia (OR: 0.50, 95% CI: 0.31-0.81, 725 women, I2 = 37%). The number of antenatal visits was significantly less in the HBPM group (standard mean difference: -0.49, 95% CI: -0.82 to -0.16, 738 women, I2 = 75%). There were no significant differences between HBPM and conventional care regarding composite maternal, fetal or neonatal outcomes when used during the antenatal period. There were no significant differences between the groups who had HBPM compared to those who had conventional care regarding postpartum readmissions and obtaining a blood pressure measurement within 10 days of delivery after discharge. The significant clinical heterogeneity and low quality of evidence are the main limitations, and therefore, more high-quality studies are needed. |
Article 4
| Citation: Tucker, K. L., Mort, S., Yu, L. M., Campbell, H., Rivero-Arias, O., Wilson, H. M., Allen, J., Band, R., Chisholm, A., Crawford, C., Dougall, G., Engonidou, L., Franssen, M., Green, M., Greenfield, S., Hinton, L., Hodgkinson, J., Lavallee, L., Leeson, P., McCourt, C., … BUMP Investigators (2022). Effect of Self-monitoring of Blood Pressure on Diagnosis of Hypertension During Higher-Risk Pregnancy: The BUMP 1 Randomized Clinical Trial. JAMA, 327(17), 1656–1665. https://doi.org/10.1001/jama.2022.4712. |
| Type of Study: Randomized Clinical Trial |
| Importance Inadequate management of elevated blood pressure (BP) is a significant contributing factor to maternal deaths. Self-monitoring of BP in the general population has been shown to improve the diagnosis and management of hypertension; however, little is known about its use in pregnancy. Objective To determine whether self-monitoring of BP in higher-risk pregnancies leads to earlier detection of pregnancy hypertension. Design, Setting, and Participants Unblinded, randomized clinical trial that included 2441 pregnant individuals at higher risk of preeclampsia and recruited at a mean of 20 weeks’ gestation from 15 hospital maternity units in England between November 2018 and October 2019. Final follow-up was completed in April 2020. Interventions Participating individuals were randomized to either BP self-monitoring with telemonitoring (n = 1223) plus usual care or usual antenatal care alone (n = 1218) without access to telemonitored BP. Main Outcomes and Measures The primary outcome was time to first recorded hypertension measured by a health care professional. Results Among 2441 participants who were randomized (mean [SD] age, 33 [5.6] years; mean gestation, 20 [1.6] weeks), 2346 (96%) completed the trial. The time from randomization to clinic recording of hypertension was not significantly different between individuals in the self-monitoring group (mean [SD], 104.3 [32.6] days) vs in the usual care group (mean [SD], 106.2 [32.0] days) (mean difference, −1.6 days [95% CI, −8.1 to 4.9]; P = .64). Eighteen serious adverse events were reported during the trial with none judged as related to the intervention (12 [1%] in the self-monitoring group vs 6 [0.5%] in the usual care group). Conclusions and Relevance Among pregnant individuals at higher risk of preeclampsia, blood pressure self-monitoring with telemonitoring, compared with usual care, did not lead to significantly earlier clinic-based detection of hypertension. |
Article 5
| Citation: Chappell, L. C., Tucker, K. L., Galal, U., Yu, L. M., Campbell, H., Rivero-Arias, O., Allen, J., Band, R., Chisholm, A., Crawford, C., Dougall, G., Engonidou, L., Franssen, M., Green, M., Greenfield, S., Hinton, L., Hodgkinson, J., Lavallee, L., Leeson, P., McCourt, C., … BUMP 2 Investigators (2022). Effect of Self-monitoring of Blood Pressure on Blood Pressure Control in Pregnant Individuals With Chronic or Gestational Hypertension: The BUMP 2 Randomized Clinical Trial. JAMA, 327(17), 1666–1678. https://doi.org/10.1001/jama.2022.4726 |
| Type of Study: Randomized Clinical Trial |
| Abstract Importance: Inadequate management of elevated blood pressure is a significant contributing factor to maternal deaths. The role of blood pressure self-monitoring in pregnancy in improving clinical outcomes for the pregnant individual and infant is unclear. Objective: To evaluate the effect of blood pressure self-monitoring, compared with usual care alone, on blood pressure control and other related maternal and infant outcomes, in individuals with pregnancy hypertension. Design, setting, and participants: Unblinded, randomized clinical trial that recruited between November 2018 and September 2019 in 15 hospital maternity units in England. Individuals with chronic hypertension (enrolled up to 37 weeks’ gestation) or with gestational hypertension (enrolled between 20 and 37 weeks’ gestation). Final follow-up was in May 2020. Interventions: Participants were randomized to either blood pressure self-monitoring using a validated monitor and a secure telemonitoring system in addition to usual care (n = 430) or to usual care alone (n = 420). Usual care comprised blood pressure measured by health care professionals at regular antenatal clinics. Main outcomes and measures: The primary maternal outcome was the difference in mean systolic blood pressure recorded by health care professionals between randomization and birth. Results: Among 454 participants with chronic hypertension (mean age, 36 years; mean gestation at entry, 20 weeks) and 396 with gestational hypertension (mean age, 34 years; mean gestation at entry, 33 weeks) who were randomized, primary outcome data were available from 444 (97.8%) and 377 (95.2%), respectively. In the chronic hypertension cohort, there was no statistically significant difference in mean systolic blood pressure for the self-monitoring groups vs the usual care group (133.8 mm Hg vs 133.6 mm Hg, respectively; adjusted mean difference, 0.03 mm Hg [95% CI, -1.73 to 1.79]). In the gestational hypertension cohort, there was also no significant difference in mean systolic blood pressure (137.6 mm Hg compared with 137.2 mm Hg; adjusted mean difference, -0.03 mm Hg [95% CI, -2.29 to 2.24]). There were 8 serious adverse events in the self-monitoring group (4 in each cohort) and 3 in the usual care group (2 in the chronic hypertension cohort and 1 in the gestational hypertension cohort). Conclusions and relevance: Among pregnant individuals with chronic or gestational hypertension, blood pressure self-monitoring with telemonitoring, compared with usual care, did not lead to significantly improved clinic-based blood pressure control. |
Article 6
| Citation: Kalafat, E., Leslie, K., Bhide, A., Thilaganathan, B., & Khalil, A. (2019). Pregnancy outcomes following home blood pressure monitoring in gestational hypertension. Pregnancy hypertension, 18, 14–20. https://doi.org/10.1016/j.preghy.2019.07.006 |
| Type of Study: Cohort study |
| Abstract Objectives: To assess the safety and efficacy of home blood pressure monitoring (HBPM) and office (traditional) blood pressure measurements in a cohort of pregnant women with gestational hypertension (GH). Study design: This was a cohort study at St. George’s Hospital, University of London conducted between December 2013 and August 2018. The inclusion criteria was pregnant women with a diagnosis of GH. Eligible patients were counseled and trained by a specialist midwife and were provided with an automated Microlife® “WatchBP Home” BP machine. Each patient followed an individualised schedule of hospital visits and BP measurements based on the HBPM pathway or standard hospital protocol which was based on the National Institute of Health and Care Excellence (NICE) guideline. Main outcome measures: Adverse fetal, neonatal and maternal outcomes as well as number of antenatal hospital visits were recorded and compared between HBPM and office (traditional) pathways. Results: 143 women with GH were included in the study (80 HBPM vs 63 standard care). There were no significant difference between the two groups in maternal high-dependency unit admission (P = 0.999), birth weight centile (P = 0.803), fetal growth restriction (p = 0.999), neonatal intensive care unit admissions (p = 0.507) and composite neonatal (p = 0.654), maternal (p = 0.999) or fetal adverse outcomes (p = 0.999). The number of Day Assessment Unit (DAU) visits was significantly lower in the HBPM group than the traditional pathway (median 4.0 vs. 5.0, P = 0.009). The difference was greater when the number of visits were adjusted for the duration of monitoring in weeks (median: 1.0 vs 1.5, P < 0.001). There were no significant difference between the two groups in the total number of outpatient (P = 0.357) and triage visits (p = 0.237). However, the total number of antenatal visits adjusted for the duration of monitoring was significantly lower for the HBPM group compared to the traditional pathway (median 1.4 vs 1.8, P = 0.020). Conclusions: HBPM in women with GH results in significantly less antenatal visits compared to women on a standard pathway of care. The two groups had comparable fetal, neonatal and maternal adverse outcomes. Large multicentre studies are needed to ascertain the safety of rare adverse pregnancy outcomes. |
Summary of the Evidence:
| Author (Date) | Level of Evidence | Sample/Setting (# of subjects/ studies, cohort definition etc. ) | Outcome(s) studied | Key Findings | Limitations and Biases |
| Yeh, P.T., et al. | Systematic review | Authors searched PubMed. CINAHL, LILACS, and EMBASE through the search date of November 9, 2020. The article included 6 studies in the effectiveness review, 7 studies in the value and preferences review, and 1 study in the cost review. | Eclampsia or pre-eclampsia Cesarean section Antenatal hospital admission Adverse pregnancy outcomes Stillbirth or perinatal death Birthweight/size for gestational age | Compared with clinic blood pressure (BP) monitoring, self-monitored blood pressure (SMBP) was associated with twice the rate of c-section among individuals with chronic hypertension, but no difference in c-section among individuals with gestational hypertension.No statistically significant difference were found between SMBP and clinic monitoring on pre-eclampsia rate, antenatal hospital admission, maternal morbidity, stillbirth or perinatal death, and lower birthweight.Most users found SMBP highly satisfactory or acceptable.SMBP was found to incur significant cost savings compared to usual care, due in part to fewer clinic visits. | The definition of SMBP was very specific, ambulatory monitoring and remote/telemonitoring were not included. The evidence base for the effectiveness, values and preferences, and cost reviews was limited. o The study did not address potential benefits of SMBP postpartum. |
| Tran. K., et al. | Systemic Review and meta-analysis | Authors searched MEDLINE (from 1946), Embase (from 1974) and CENTRAL (from 2018) databases up to Oct. 19, 2020. The article included 19 individual studies (18 observational studies and 1 RTC), totaling 2843 pregnant participants. | Diagnostic thresholds for home blood pressure measurements Comparison between home and office blood pressure measurements Maternal pregnancy outcomes (hypertensive disorders of pregnancy, preeclampsia Fetal outcomes | Diagnostic thresholds for hypertension in third trimester of pregnancy ranges from 118 to 143 mmHg for systolic blood pressure and from 76 to 92 mmHg for diastolic blood pressure.Mean home blood pressure was lower than mean office blood pressure in pregnant individuals by a small amount, but with substantial variation in this difference across studies.2 studies noted no difference in maternal or fetal outcomes between home blood pressure monitoring and usual care in the maternity day unit.Home blood pressure monitoring was associated with a reduction in hypertension-related visits (6.5 visits vs. 8 visits) | Search was limited to English publications and omitted grey literature. Lack of contemporary RCTs on this topic. o The quality of available data was poor. |
| Kalafat, E. , et al. | Systemic review and meta-analysis | Authors searched Medline, EMBASE and the Cochrane library electronically in May 2019. 9 studies were included in this meta-analysis, with a total of 684 patients on home blood pressure monitoring | Labor induction Prenatal hospital admission Diagnosis of preeclampsia | The use of home blood pressure monitor (HBPM) is associated with significant reductions in the number of antenatal visits, prenatal hospital admissions by 70%, diagnosis of preeclampsia by 50% and 45% fewer induction of labor.HBPM was not associated with increased risk of adverse maternal or perinatal outcomes compared to conventional care. | The number of included studies for each subgroup is low. Most studies used monitors that are not validated for use in pregnancy. Unable to perform subgroup/sensitivity analyses with meta-regression to address important variables such as telemetry use due to the small number of included studies. Studies included show significant clinical heterogeneity and most of the evidence stems from observational studies with inherent limitations. |
| Tucker K., et al. | Randomized Clinical Trial | This trial was an unblinded RCT. The trial was conducted in UK from 2018 – 2020. A total of 2441 participants were included in the study and 2346 of them completed the trial. | Primary: Difference in the time from randomization to first recording of “clinical hypertension” Secondary: Maternal and perinatal complications | The primary outcome was difference in the time from randomization to first recording of “clinic hypertension”. The primary outcome was not significantly different between individuals who self-monitored or received usual prenatal care alone. There was no statistically significant difference in the incidence of severe hypertension or in the incidence of preeclampsia between the group.There was no significant difference in the proportion with spontaneous onset of labor.Anxiety was not significantly different between groups at either 30 weeks gestation or postnatally.There was no significant differences in neonatal unit admission. | The study was not powered to detect differences in clinical outcomes. Some patients had self-monitored prior to randomization, which might dilute some effect of the intervention. The threshold for hypertension diagnosis with SMBP in pregnancy is not established. |
| Chappell. L, et al. | Randomized Clinical Trial | This is an unblinded, randomized clinical trial conducted in UK between November 2018 and September 2019. 850 individuals with chronic hypertension or gestational hypertension were enrolled. | Primary: difference in mean systolic BP, defined as the mean of BPs recorded by health care professional in the clinical record from date of entry into the study plus 1 day, until date of delivery minus 1 day, between usual care and self-monitoring groups. Secondary: maternal outcomes, maternal complications, onset of labor, and perinatal outcomes. | There was no significant difference in the mean systolic BP among those allocated to self-monitoring blood pressure (SMBP), in either the chronic or gestational hypertension groups.Among participants with chronic hypertension, the mean clinic systolic BP was 133.8 mmHg in the SMBP group compared with 133.6 mmHg in usual care group.Among participants with gestational hypertension, the mean systolic BP was 137.6 mmHg in the SMBP group compared with 137.2 mmHg in usual care group.Among individuals with chronic hypertension, there was no significant difference in the majority of maternal and infant secondary outcomes, other than a lower proportion with spontaneous onset of labor: 12 participants in the SMBP groups vs. 21 participants in the usual care group. There was no significant difference in gestational age at birth, spontaneous vaginal birth, or in any of the infant outcomes.Among participants with gestational hypertension, there were no significant different in the maternal and infant secondary outcomes, other than a lower proportion of individuals with a spontaneous onset of labor: 31 individuals in the SMBP group vs 44 individuals in the usual care group.There were no significant differences in anxiety and adherence measures at baseline or follow-up.There were no significant differences in adverse events or serious adverse events between the 2 groups. | There was uncertain use of SMBP by the usual care group during the trial. Participants reporting self-monitoring prior to randomization may have diluted the intervention effect. The SMBP did not include other factors such as automated transfer of BP readings to the electronic health record, self-managed titration of antihypertension medication, or life-style counselling that might have improved effectiveness. |
| Kalafat E., et al. | Cohort study | This was a cohort study conducted in UK between December 2013 and August 2018. The study included 143 participants. (80 HBPM vs 63 standard care) | Adverse fetal, neonatal and maternal outcomes Number of antenatal hospital visists | The incidence pf preterm birth prior to 34 weeks was similar between the two groups.The incidence of vaginal delivery, operative delivery and elective cesarean section were similar between the two groups.No significant differences were observed regarding maternal high-dependency unit admission, birth weight cetile, fetal growth restriction, neonatal intensive care unit admissions and composite neonatal, maternal, or fetal adverse outcomes.HBPM significantly reduced the number of antenatal visits. | Possibility for intervention or selection because the study’s observational design.Women with severe preeclampsia, systolic BP above 155 mmHg, diastolic BP above 100 mmHg, significant proteinuria, FGR, mental health disorder or insufficient understanding of English language were not included. The study cannot provide robust evidence on these situations. |
Conclusions:
Article 1 (Yeh, P.T., et al.) : Self-monitoring blood pressure is commonly available and generally accepted by patients. The data suggests that maternal and neonatal health outcomes are similar to that of clinic-based monitoring. Therefore, it can be an additional option for monitoring blood pressure during antenatal period.
Article 2 (Tran. K., et al.): Current studies do not provide adequate guidance with respect to the use of home blood pressure monitoring in pregnancy. There is a lack of contemporary RCTs on this topic. Its implementation is uncertain.
Article 3 (Kalafat, E. , et al.): The number of antenatal visits was significantly less in the home-based blood pressure group. There was no significant difference between conventional care and home-based blood pressure monitoring regarding composite maternal, fetal, or neonatal outcomes.
Article 4 (Tucker K., et al.): Compared to conventional care, blood pressure self-monitoring with telemonitoring did not lead to significantly earlier clinical-based detection of hypertension in pregnant patients who are at higher risk for preeclampsia.
Article 5 (Chappell. L, et al.): In pregnant patients with chronic or gestational hypertension, self-monitoring blood pressure with telemonitoring did not lead to significantly improved clinic-based BP control when compared to usual care.
Article 6 (Kalafat, E. , et al.): HBPM in women with gestational hypertension results in significantly less antenatal visits than women on a standard pathway of care. These two groups had comparable adverse maternal and perinatal outcomes.
Overall conclusion
HBPM could reduce the number of in-person antennal visits. However, among general pregnant individuals, individuals with high risk for preeclampsia, and individuals with chronic or gestational hypertension, HBPM leads to similar maternal and neonatal outcomes when compared to conventional in-office care.
Clinical bottom line:
I weight the level of evidence in this order: Article 4 > Article 5 > Article 2 > Article 1 > Article 3> Article 6
Article 4 (Tucker K., et al.): I weighted this article the highest. This is a recent RCT published in 2022 and was not included in the other systemic revies. Compared to the RTCs included in the other systemic review, this RTC has higher quality in terms of sample size. The articles included 2441 pregnant patients at increased risk for preeclampsia. The patient population fits the patient in the clinical scenario. The objective of this trial was to investigate whether self-monitoring of BP during pregnancy lead to earlier detection of pregnancy hypertension. The objective is applicable to PICO question. The other systemic reviews included older RTCs with smaller sample size. Therefore, I think this RTC is superior in its level of evidence.
Article 5 (Chappell. L, et al.): I weighted this article the 2nd for the similar reason. This is a randomized controlled trials published in 2022. The articles included 850 pregnant patients with chronic hypertension or gestational hypertension. The objective of this trial was to investigate the effect of self-monitoring of BP during pregnancy on blood pressure control and other related maternal and infant outcomes. This RTC is more recent with larger sample size when compared to the RTCs included in the other systemic reviews. Therefore I’m more confident about its results.
Article 2 (Tran. K., et al.): This is a systematic review and meta-analysis that assess the effectiveness of home blood pressure monitoring in pregnancy. The authors conducted search through MEDLINE, Embase, and CENTRAL databases up to 10/19/2020. They included 21 articles from 19 individual studies (18 observational studies and 1 RCT). They included data from 2495 patients in this review. It has a relatively large sample size, but most of the data were derived from observational studies.
Article 1 (Yeh, P.T., et al.) This is a recent systemic review published in 2022. The authors conducted search across multiple databases including PubMed. CINAHL, LILACS, and EMBASE through the search date of November 9, 2020. This review included data from 6 studies (1 RTC and 5 observational studies). Even though it is published in the same year as article 2, this systemic review contains fewer studies.
Article 3 (Kalafat, E. , et al.): This is a systematic review published in 2020. The authors searched MEDLINE, EMBASE, and the Cochrane library databases and included 9 studies (3 RTCs and 6 cohort studies) in this review and analysis. However, the RTCs included were all with small sample size and the studies included were older compared to other systemic reviews.
Article 6 (Kalafat, E. , et al.): This is a cohort study with 143 participants. Due to it’s study design and sample size, the level of evidence is lower compared to the other studies.
Magnitude of any effects:
Article 6 (Kalafat, E. , et al.): HBPM pathway significantly reduced the number of DAU visits
(median 4.0 vs. 5.0, P=0.009) (Table 2). The difference was greater when the number of visits were adjusted for the duration of monitoring in weeks (median: 1.0 vs 1.5, P < 0.001). The total number of antenatal visits adjusted for the duration of monitoring was significantly lower for the HBPM group compared to controls (median 1.4 vs 1.8, P=0.020).
Besides the decreased number of in-person visits, the magnitude of effect is not high in other aspects. All the other studies concluded that there is no significant difference between HMBP and conventional care in terms of maternal and neonatal outcomes/complications
Clinical significance:
The conclusions of the articles show self-monitoring of blood pressure during pregnancy does not lead to improved clinical outcomes when compared to usual prenatal visit. The two recent RCTs showed that the clinical outcomes are similar even among pregnant individuals with higher risk of preeclampsia, and individuals with chronic hypertension and gestational hypertension. There is also no data reporting adverse effect associated with home monitoring of blood pressure. Therefore, I would not against if patient would like to monitor their blood pressure. I would also emphasize that home-monitoring does not replace regular prenatal visits. Patients should still be seen by the provider on a regular basis.
Any other considerations important in weighing this evidence to guide practice – If the evidence you retrieved was not enough to conclude an answer to the question, discuss what aspects still need to be explored and what the next studies will have to answer/provide (e.g. larger number, higher level of evidence, answer which sub-group benefits, etc)
Even though the above studies showed that home-monitoring BP does not lead to better clinical outcomes, it might still be beneficial for patients with white coat syndrome and patients in rural area who have limited access to in-person health care. In addition, majority of the studies include in the systemic reviews were observational studies. There is a need for more RCTs investigating the use of home BP monitor in different patient population.
Article 1: https://bmcpregnancychildbirth.biomedcentral.com/articles/10.1186/s12884-022-04751-7
Article 2: https://pubmed.ncbi.nlm.nih.gov/34131027/
Article 3: https://pubmed.ncbi.nlm.nih.gov/31901652/
Article 4: https://jamanetwork.com/journals/jama/article-abstract/2791695
Article 5: https://jamanetwork.com/journals/jama/article-abstract/2791694
Article 6: https://www.sciencedirect.com/scence/article/abs/pii/S2210778919300868?via%3Dihub
