Severe Hypertension in Pregnancy
Severe hypertension in pregnancy is defined as systolic blood pressure ≥160 mmHg and/or diastolic blood pressure ≥110 mmHg, which requires urgent treatment within 15 minutes to prevent maternal stroke and death. 1
Blood Pressure Thresholds
The definition is based on absolute blood pressure values that distinguish severity levels:
This lower threshold for severe hypertension in pregnancy (compared to ≥180/110-120 mmHg outside pregnancy) reflects the increased risk for adverse maternal outcomes, particularly stroke and death. 2
Confirmation Requirements
When severe blood pressure is detected (≥160/110 mmHg), it should be confirmed within 15 minutes, not hours. 1 This rapid confirmation timeline distinguishes severe hypertension from less severe elevations, where repeated readings can be taken over several hours. 1
Clinical Significance and Urgency
Severe hypertension represents a hypertensive emergency requiring:
- Immediate treatment in a monitored setting 3, 4, 5
- Initiation of antihypertensive therapy within 30-60 minutes of recognition 2
- Treatment goal of systolic BP 140-150 mmHg and diastolic BP 90-100 mmHg 3, 5
The urgency stems from the association with increased stroke risk and represents a maternal indication for delivery if blood pressure remains uncontrollable despite ≥3 classes of antihypertensive medications in appropriate doses. 3
First-Line Treatment Agents
For acute severe hypertension, acceptable first-line agents include:
- Intravenous labetalol 3, 5, 2
- Intravenous hydralazine 3, 5, 2
- Oral immediate-release nifedipine 3, 4, 2
Context Across Hypertensive Disorders
This definition of severe hypertension applies regardless of the specific hypertensive disorder type (pre-existing hypertension, gestational hypertension, preeclampsia, or superimposed hypertension). 1 The blood pressure threshold itself determines severity and urgency of management, independent of the underlying classification.