Study links Postpartum BP Control to Readmission: Implications for Maternal Health Strategies

In the large, national dataset, there was a significant correlation between BP control at discharge and readmission in the postpartum period.

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 significantly contributes to the increasing maternal mortality rates, with a significant proportion of maternal deaths occurring post-delivery. Research has indicated that the highest recorded blood pressure during labor and delivery admission can forecast the likelihood of readmission. However, the ideal blood pressure threshold to minimize readmissions and the necessity for further medical intervention during the postpartum phase remains uncertain.

Elevated BP during the postpartum period can lead to complications such as preeclampsia, eclampsia, or stroke, necessitating hospital readmission. Considering this, 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 Cosmos, an electronic health record–based, Health Insurance Portability and Accountability Act–defined limited dataset that includes more than 1.4 million birth encounters.

All postpartum individuals with recorded blood pressure measurements post-delivery were included in the study. Data on demographics, medications, and hospital readmissions were extracted from the dataset. Patients were categorized based on their blood pressure readings within the 24 hours before discharge, specifically ≥160/110, ≥150/100, ≥140/90, ≥130/80, ≥120/80, and <120/80 mm Hg. The study compared readmission rates across these defined blood pressure groups. Planned subgroup analyses involved stratification using antihypertensive medications, and a sensitivity analysis was conducted using the highest blood pressure recorded during hospital admission. Covariates considered in the analysis included maternal age, preexisting conditions such as diabetes mellitus or lupus erythematosus, and body mass index.

The following were the key findings of the study:

• The analysis included 1,265,766 total birth encounters, 391,781 in the referent group (120/80 mm Hg), 392,592 in the group with <120/80 mm Hg, 249,414 in the group with ≥130/80 mm Hg, 16,125 in the group with ≥140/90 mm Hg, 50,659 in the group with ≥150/100 mm Hg, and 20,196 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 blood pressure reading fell into the referent group (120/80 mm Hg) (odds ratio [OR], 2.90; 95% confidence interval, 2.69–3.12).
• 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 odds of readmission (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 BP categories, patients who received an antihypertensive prescription had higher readmission rates.

In conclusion, as healthcare continues to prioritize maternal health and safety, studies like these underscore the critical role of postpartum blood pressure management in preventing readmissions. By implementing evidence-based practices and personalized care strategies, healthcare providers can optimize outcomes and support maternal well-being post-delivery.

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