(597) De novo hypertension in the late postpartum period: a case for extending postpartum care

To better inform efforts to improve and extend postpartum (PP) care, we sought to determine the incidence of de novo hypertension (HTN) up to 6 months PP in patients without evidence of HTN during pregnancy or immediately PP.

Study Design:

This retrospective cohort study included all patients delivering within an academic healthcare system. All blood pressures (BPs) from conception to 6 months PP were obtained from the electronic medical record (EMR) and used to construct a variable identifying patients with ≥ 2 systolic BPs ≥ 140 mm Hg or ≥ 2 diastolic BPs ≥ 90 mm Hg from conception to delivery encounter discharge. We excluded patients with an ICD code for chronic HTN or HDP hypertensive disorders of pregnancy in the EMR or evidence of HTN by our constructed variable. All BPs from the early PP period (delivery discharge to 6 weeks; EPP) and the late PP period (6 weeks to 6 months; LPP) were used to classify patients into one of four HTN stages per American College of Cardiology definitions (normotensive, elevated, stage 1 and stage 2). HTN stages in the LPP for the subset of patients who were also normotensive in the EPP were then examined to assess the risk of late-onset de novo HTN that would not otherwise be captured during standard postpartum care. We evaluated patient attributes associated with a new diagnosis of HTN in the LPP using Χ² tests.

Results:

In total, 18,270 patients were included. Despite normotensive pregnancies, 12.6% were elevated, 11.7% were stage 1, and 1.3% were stage 2 in the LPP (Table). Traditional risk factors for HTN (smoking, diabetes, age ≥ 35, and obesity) were observed more frequently in those who developed de novo HTN. Of the 7,872 patients who were normotensive in the EPP, 9.6% were subsequently classified as elevated, 7.7% as stage 1, and 0.5% as stage 2 HTN.

Conclusion:

Even in the absence of evidence of HTN during pregnancy and early PP, many patients remain at risk for development of de novo HTN up to 6 months PP. Expansion of postpartum care may provide an opportunity to identify these patients and triage appropriate clinical care.