What is the blood pressure cutoff for starting antihypertensive treatment in a pregnant woman with gestational hypertension according to the NICE (National Institute for Health and Care Excellence) guideline 2023?

NICE 2023 Blood Pressure Cutoff for Starting Antihypertensive Treatment in Pregnancy

Based on the most current international guidelines, antihypertensive treatment should be initiated when blood pressure reaches ≥140/90 mmHg in pregnant women with gestational hypertension, targeting a diastolic BP of 85 mmHg and systolic BP between 110-140 mmHg. 1

Treatment Thresholds

For gestational hypertension specifically, the threshold for initiating pharmacological treatment is ≥140/90 mmHg. 1, 2 This recommendation is supported by:

• The International Society for the Study of Hypertension in Pregnancy (ISSHP), which explicitly recommends starting antihypertensive medications at ≥140/90 mmHg in women with gestational hypertension, pre-existing hypertension with superimposed gestational hypertension, or hypertension with organ damage 1, 3

• The European Society of Cardiology guidelines, which recommend initiating drug treatment at BP ≥140/90 mmHg in women with gestational hypertension (with or without proteinuria) 3, 4

Target Blood Pressure Range

Once treatment is initiated, the goal is to maintain:

• Diastolic BP at 85 mmHg 5, 1, 2
• Systolic BP between 110-140 mmHg 5, 1, 2

Antihypertensive drugs should be reduced or ceased if diastolic BP falls below 80 mmHg, as this may compromise uteroplacental perfusion and increase the risk of small-for-gestational-age infants 1, 2

Severe Hypertension Threshold

Blood pressure ≥160/110 mmHg requires urgent treatment within 15-60 minutes in a monitored setting to prevent maternal stroke and other end-organ damage 1, 2, 6. This represents a hypertensive emergency and should never remain elevated for more than 15 minutes 1

First-Line Medications

Acceptable first-line oral agents include:

• Methyldopa 5, 2, 4
• Labetalol 5, 2, 4
• Long-acting nifedipine 5, 2, 6

For acute severe hypertension (≥160/110 mmHg), use oral nifedipine or intravenous labetalol or hydralazine 5, 2

Evidence Supporting Earlier Treatment

The CHAP trial (2022) demonstrated that treating mild chronic hypertension with a target BP <140/90 mmHg resulted in better pregnancy outcomes compared to reserving treatment only for severe hypertension, with no increase in small-for-gestational-age births 7. This supports the rationale for the 140/90 mmHg threshold in gestational hypertension as well 1

Critical Monitoring Points

• Approximately 25% of women with gestational hypertension will progress to preeclampsia, making close monitoring essential 5, 3
• Blood pressure should be monitored at each prenatal visit with screening for proteinuria if BP reaches ≥140/90 mmHg 3
• Women with gestational hypertension require hospital assessment if they develop severe hypertension ≥160/110 mmHg or features of preeclampsia 5