OBJECTIVE: Severe hypertension (two systolic blood pressure [BP] values ≥ 160 mm Hg or diastolic BP values ≥ 110 mm Hg, 15-60 min apart) is a modifiable cause of maternal morbidity and mortality. We aimed to assess the impact of a quality improvement (QI) intervention to optimize the management of severe hypertension during pregnancy and postpartum. STUDY DESIGN: We developed and implemented a QI intervention for severe hypertension management at a Canadian tertiary care center and conducted a quasi-experimental pre- and post-intervention cohort study. Pregnant and postpartum patients with a hypertensive disorder of pregnancy (HDP) between 2020 and 2022 were identified, and pre- and post-intervention cohorts were constructed. MAIN OUTCOME MEASURES: Severe hypertension management was assessed according to quality indicators, including time-to-target BP within 60 min and use of appropriate antihypertensive therapy. RESULTS: Among 697 patients with HDP, 134 (19 %) experienced severe hypertension (pre-intervention: n = 56
post-intervention: n = 78). Immediate release oral nifedipine was the most frequently used medication to treat severe hypertension episodes (63 %). Median time-to-target BP was 49.5 min pre-intervention (interquartile range [IQR] 28.0-69.8) vs. 33.5 min (IQR 19.8-65.2) post-intervention (p = 0.102). Time-to-target BP within 60 min was achieved in 64 % of patients pre- vs. 74 % post-intervention (p = 0.209), meeting our pre-established institutional target. Appropriate antihypertensive administration increased from 55 % pre-intervention to 76 % post-intervention (p = 0.014). CONCLUSION: Developing and implementing a QI intervention resulted in achievement of our institutional target for time-to-severe hypertension resolution and increased use of appropriate antihypertensive medications. Standardized protocols and QI interventions can optimize severe hypertension management to reduce severe maternal morbidity.