The clinical interchangeability of nocturnal blood pressure (BP) measurements obtained by home blood pressure monitoring (HBPM) and 24-hour ambulatory blood pressure monitoring (ABPM) during pregnancy remains uncertain. A cohort study with a cross-sectional analysis presented at the ESH Congress 2026 evaluated the comparability of these methods in women with high-risk pregnancies.
The study included pregnant women between 20 and 24 weeks of gestation who underwent office BP measurement, 24-hour ABPM, and nocturnal HBPM using validated devices. After ABPM removal, participants performed nocturnal HBPM over three consecutive nights with automated nighttime measurements. Agreement and interchangeability between methods were evaluated using correlation, Bland-Altman analysis, intraclass correlation coefficients, and diagnostic concordance for nocturnal hypertension
Findings
- Mean nocturnal systolic and diastolic BP values were similar between ABPM and HBPM(SBP: 104±11.1 vs 103±10.2 mmHg, p=0.139; DBP: 60±7.0 vs 61±7.3 mmHg, p=0.808). .
- Moderate correlations were observed between methods for nocturnal systolic BP (r=0.63) and diastolic BP (r=0.60).
- Bland-Altman analysis showed wide limits of agreement, with inter-method differences greater than 5 mmHg in 39% of systolic BP and 35% of diastolic measurements.
- Intraclass correlation coefficients indicated moderate agreement for systolic BP (0.57-0.63) and diastolic BP (0.60).
- Diagnostic concordance for nocturnal hypertension was moderate (kappa=0.47).
The findings suggest that although nocturnal HBPM and ABPM provide comparable average nocturnal BPestimates in high-risk pregnancy, agreement at the individual level remains limited. The results indicate that the two methods should not be considered clinically interchangeable.
