What is the normal blood pressure range for a pregnant woman?

From the Guidelines

Normal blood pressure for a pregnant woman is typically considered to be below 126/76 mmHg for a 24-hour average, 132/79 mmHg for awake average, and 114/66 mmHg for sleep average, as defined by 24-hour ambulatory blood pressure monitoring (ABPM) before 22 weeks of gestation 1.

Key Considerations

• Blood pressure should be monitored regularly throughout pregnancy, as it can fluctuate due to hormonal shifts and increased blood volume.
• The first trimester is a critical period for defining normal or high blood pressure, as many women may not have had their blood pressure measured before becoming pregnant.
• Home blood pressure monitoring or 24-hour ABPM can help identify white-coat hypertension and provide a more accurate assessment of blood pressure.

Monitoring and Management

• All women should have their home blood pressure device checked against a calibrated sphygmomanometer or automated device validated for use in pregnancy and preeclampsia before using it to monitor their blood pressure.
• Average blood pressure over several days should be relied upon rather than acting on single readings for women monitoring home blood pressure values, unless there is severe hypertension (≥160/110 mm Hg).
• Regular prenatal visits are essential for monitoring blood pressure changes, and any sudden increases, especially when accompanied by symptoms like headaches, vision changes, or swelling, should prompt immediate medical consultation 1.

Importance of Accurate Blood Pressure Measurement

• Accurate blood pressure measurement is crucial for diagnosing and managing hypertensive disorders in pregnancy, which can pose serious risks to both mother and baby if left untreated.
• The International Society for the Study of Hypertension in Pregnancy (ISSHP) recommends that all women with chronic hypertension in pregnancy have baseline tests performed at first diagnosis, including a full blood count, liver enzymes, and serum creatinine, to provide a reference for later comparison 1.

From the Research

Normal Blood Pressure Range for Pregnant Women

• The normal blood pressure range for pregnant women is not explicitly defined in the provided studies, but hypertension in pregnancy is defined as systolic blood pressure ≥ 140 and/or diastolic blood pressure ≥ 90 mmHg 2.
• A study published in 2023 found that blood pressures of 120-139/80-89 mmHg before 20 weeks of gestation may be associated with an increased risk of hypertensive disorders of pregnancy 3.
• The American College of Obstetricians and Gynecologists defines hypertension in pregnancy as a systolic blood pressure higher than 140 mmHg or a diastolic blood pressure higher than 90 mmHg 3, 4.
• The European guidelines recommend initiating drug treatment in pregnant women with persistent elevation of blood pressure ≥ 150/95 mmHg and at values > 140/90 mmHg in women with gestational hypertension 4.

Blood Pressure Thresholds for Treatment

• Severe hypertension in pregnancy is typically defined as systolic blood pressure ≥ 160 mmHg or diastolic blood pressure ≥ 110 mmHg 5.
• Hospitalization is indicated for systolic blood pressure ≥ 170 or diastolic blood pressure ≥ 110 mmHg 4.
• Treatment of mild or moderate hypertension in pregnancy is less clear, but antihypertensive drugs may be valuable in reducing the risks directly due to elevated blood pressure 6.