Effective Postpartum Blood Pressure Control Linked to Reduced Readmission Rates: Study

In the large, national dataset, blood pressure (BP) control at discharge and readmission in the postpartum period were significantly correlated. The findings, published in the American Journal of Obstetrics & Gynecology MFM, should inform postpartum hypertension treatment goals and the role of remote monitoring programs in improving maternal safety.

Postpartum hypertension, characterized by elevated blood pressure levels after delivery, is a common concern affecting a significant number of women. While often transient, uncontrolled hypertension in the postpartum period can lead to severe complications such as eclampsia, stroke, and organ damage. Despite its potential risks, the optimal approach to managing postpartum blood pressure and its impact on readmission rates have been subjects of ongoing debate and investigation.

Previous studies have found evidence that the maximum BP reading during labor and delivery admission can predict readmission; however, the optimal BP to reduce the readmissions needed and additional medical treatment in the postpartum period is unknown.

To fill this knowledge gap, Kelly S. Gibson, The MetroHealth System/Case Western Reserve University, Cleveland, OH, and colleagues aimed to investigate the relationship between postpartum BP control at discharge and readmission within the first six weeks after delivery.

For this purpose, the researchers obtained data from the Cosmos, an electronic health record–based, Health Insurance Portability and Accountability Act–defined limited dataset comprising more than 1.4 million birth encounters. The study included all birthing parents with blood pressure data after delivery. Medications, demographic information, and readmissions were queried from the dataset.

Based on BP readings in the 24 hours before discharge, the patients were grouped into categories (≥160/110, ≥150/100, ≥140/90, ≥130/80, ≥120/80, and <120/80 mm Hg). The readmission rates were compared across these groups.

Planned sub-analyses included stratification using antihypertensive medications and a sensitivity analysis using the highest BP during admission. Covariates included preexisting diabetes mellitus or lupus erythematosus, maternal age, and body mass index.

The researchers reported the following findings:

• The analysis included 1,265,766 total birth encounters, 30.9% in the referent group (120/80 mm Hg), 31.0% in the group with <120/80 mm Hg, 19.7% in the group with ≥130/80 mm Hg, 1.3% in the group with ≥140/90 mm Hg, 4.0% in the group with ≥150/100 mm Hg, and 1.6% in the group with ≥160/110 mm Hg.
• In the first six weeks after delivery, readmission rates increased with higher blood pressure readings.
• More than 5% of postpartum patients with the highest blood pressure readings (≥160/110 mm Hg) were readmitted. These patients were almost three times more likely to be readmitted than patients whose highest BP reading fell into the referent group (120/80 mm Hg) (odds ratio [OR], 2.90).
• Patients with blood pressures of >150/100 mm Hg (odds ratio, 2.72), >140/90 mm Hg (odds ratio, 2.03), and >130/80 mm Hg (odds ratio, 1.43) all had higher odds of readmission, whereas patients with a blood pressure of <120/80 mm Hg had a lower readmission odds (odds ratio, 0.78).
• Patients who had higher blood pressures during admission but had improved control in the 24 hours before discharge had lower readmission rates than those whose blood pressures remained elevated.
• In all blood pressure categories, patients who received an antihypertensive prescription had higher readmission rates.

While further research is needed to explore the most effective strategies for postpartum blood pressure management, this study represents a significant step forward in advancing our understanding of maternal health in the postpartum period. By identifying key factors associated with readmission rates, researchers aim to inform clinical practice guidelines and ultimately enhance outcomes for postpartum women and their infants.

Reference:

Gibson, K. S., Olson, D., Lindberg, W., Keane, G., Keogh, T., Ranzini, A. C., Alban, C., & Haddock, J. (2024). Postpartum blood pressure control and the rate of readmission. American Journal of Obstetrics & Gynecology MFM, 6(7), 101384. https://doi.org/10.1016/j.ajogmf.2024.101384