Postpartum readmission, defined as readmission within the six weeks following delivery, occurs in 0.4–5% of pregnancies [1], [2], [3]. The postpartum period is a high-risk time for maternal morbidity and mortality with > 60% of all maternal deaths occurring during this period, 7% of which are attributed to hypertensive disorders of pregnancy [4], [5], [6]. Postpartum readmission for hypertension is associated with multiple adverse effects including significant economic impact and cost [7], [8]. Multiple risk factors, including severe range blood pressures (systolic ≥ 160 mmHg and/or diastolic ≥ 110 mmHg) prior to discharge following delivery, have been identified for postpartum readmission. In response, multiple hospital-based systems and protocols have been implemented in an effort to reduce the risk of readmission [3], [9].

The American College of Obstetricians and Gynecologists (ACOG) defines hypertensive disorders of pregnancy as a systolic blood pressure ≥ 140 or diastolic blood pressure ≥ 90 on two separate occasions, which is congruent with prior guidelines from the American Heart Association (AHA) and the American College of Cardiology (ACA) [10]. Since 2017, however, the AHA/ACA have redefined HTN at a lower threshold such that BP ≥ 140/90 mmHg is stage 2 hypertension, and BP ≥ 130/80 mmHg is stage 1 hypertension [11]. Current obstetric guidelines advocate for the treatment of mild chronic hypertension in pregnancy with the goal to maintain average blood pressure less than 140 mmHg systolic and 90 mmHg diastolic [12]. Prior data note associations between postpartum readmission and severe blood pressure in the postpartum period. No guidelines exist regarding treatment and goal blood pressure in the postpartum period, particularly in the setting of stage 1 or stage 2 hypertension [13], [14].

In this study we sought to evaluate the risk of postpartum readmission in patients with normal blood pressure in the immediate postpartum period, compared to those with stage 1 hypertension, and stage 2 hypertension. We hypothesized that patients with stage 1 hypertension are at similar risk for readmission as those with stage 2 hypertension.