Twenty-Four-Hour Mean Arterial Pressure and Pulse Pressure Are Associated with Hospitalization Duration at Delivery in Pregnant Women Referred for Cardiovascular Risk Assessment

Background: We evaluated the relationship between ambulatory blood pressure monitoring (ABPM) indices and prolonged hospitalization at delivery in pregnant women referred for ABPM assessment. Methods: This was a prospective observational study including 132 pregnant women, followed until delivery. Office and 24 h ABPM measurements were obtained early in pregnancy and mean arterial pressure (MAP) and pulse pressure (PP) were derived. Prolonged hospitalization was operationally defined as above-median length of stay in the study cohort (>4 days). Associations with prolonged hospitalization were evaluated using binary logistic regression models, while time to hospital discharge was analyzed using Cox proportional hazards regression. Discriminative performance was assessed using receiver operating characteristic (ROC) curve analysis, and time-to-event data were explored using Kaplan–Meier curves. Results: Prolonged hospitalization occurred in 33.3% of patients. In multivariate analyses, 24-hMAP (OR 1.64, 95% CI 1.05–2.55; p = 0.029) and 24-hPP (OR 1.71, 95% CI 1.06–2.74; p = 0.027) were independently associated with prolonged hospitalization. ROC curve analysis demonstrated AUC values of 0.866 and 0.859 for the 24-hMAP and 24-hPP models, respectively. At a 30% false-positive rate, the 24-hMAP model achieved approximately 90% sensitivity, whereas the 24-hPP model achieved approximately 90% specificity at a 30% false-negative rate. In time-to-event analyses, only 24 h MAP remained independently associated with time to hospital discharge (HR 0.75, 95% CI 0.62–0.89; p = 0.001). Conclusions: Both 24-hMAP and 24-hPP were independently associated with prolonged hospitalization whereas office BP-derived indices were not. These findings support that integrated ABPM-derived measures may provide complementary prognostic information beyond conventional BP assessments.