Blood Pressure Thresholds in Pregnancy for Identifying Maternal and Infant Risk: A Secondary Analysis of Community-Level Interventions for Pre-Eclampsia (CLIP) Trial Data

Abstract

Although this is a single study of the use of telemedicine for prenatal care, it is reassuring that there were no large obvious differences in outcomes with fewer in person visits. There are certainly great efficiencies to be gained for patients to not have to come in person for many prenatal care visits. One screening tool that is useful throughout the third trimester is blood pressure checks, so if one was going to have a large proportion of prenatal care visits become virtual, having a home blood pressure cuff would be an important adjunct to care. As many health systems and providers around the globe began rapid adoption of telemedicine during the pandemic, we will want exploration of this question from multiple settings and in varied patient populations. Although we may see continued use of telemedicine for prenatal care beyond the pandemic, the biggest benefit will likely come from expansion of subspecialty care to higher-risk populations. It is in these populations that additional studies would be most welcome.-ABC)

Blood pressure measurement and adverse pregnancy outcomes: A cohort study testing blood pressure variability and alternatives to 140/90 mmHg

“…While there was some evidence of reverse causality for maternal outcomes, associations remained between higher BPV and adverse outcomes, and the direction of effect was the same for maternal and perinatal outcomes. 12 Analyses within the hypertensive subpopulation (as in CHIPS) confirmed an association between higher BPV and more adverse maternal and perinatal outcomes. Furthermore, two large publications (101 100 total participants) have found an association between higher BPV and more SGA infants, with mixed results for other perinatal outcomes.…”

“…6 Six previous studies have explored the relationship between BPV and adverse outcomes in pregnancy; results have been conflicting with regard to a relationship between BPV and adverse maternal and/or perinatal outcomes, and whether higher BPV is predictive of adverse outcomes or represents a manifestation of them. [7][8][9][10][11][12][13]…”

“…In addition to higher BP level, higher long‐term visit‐to‐visit BP variability (BPV) is a risk factor for cardiovascular disease outside pregnancy, even when adjusted for BP level 6 . Six previous studies have explored the relationship between BPV and adverse outcomes in pregnancy; results have been conflicting with regard to a relationship between BPV and adverse maternal and/or perinatal outcomes, and whether higher BPV is predictive of adverse outcomes or represents a manifestation of them 7‐13 …”

Choosing blood pressure thresholds to inform pregnancy care in the community: An analysis of cluster trials

“…Importantly, no BP category, even normotension‐2, had even a fair −LR, suggesting that a normal BP is not useful in identifying women at low risk of developing adverse outcomes in the future. In this dataset previously, we determined that the same was true for the 130/80 mmHg (‘Stage 1 hypertension’) and 120 mmHg systolic (‘Elevated BP’) recommended outside pregnancy by 2017 American guidelines 16,17 . A normal BP must be repeated on a regular basis to ensure that it remains normal, and should remain an auditable standard for antenatal care 6 .…”

“…Using population‐level, 3AS1‐2®‐derived data from the three Community‐Level Interventions for Pre‐eclampsia (CLIP) trials, 12–15 we have shown that diagnostic BP thresholds in pregnancy should not be lowered to those suggested by the American College of Cardiology and the American Heart Association (ACC‐AHA) 16,17 . However, a recent Delphi consensus has supported using BP values that are 5 mmHg lower when measured in a community (such as at home), compared with office BP values; 18 this means that 140/90 mmHg in the office would be equivalent to 135/85 mmHg in the community, and 160/110 mmHg equivalent to 155/105 mmHg.…”