Drugs for High Blood Pressure in Pregnancy

Author: Samreen Usman, Pharm-D, MPhil (Pharmaceutical Chemistry)

Medical Reviewer: Dr Azuka Chinweokwu Ezeike, MBBS, FWACS, FMCOG, MSc (PH)

Highlights

High blood pressure during pregnancy can pose serious risks to both mother and baby if not properly managed.
Early diagnosis and regular blood pressure monitoring are essential to prevent complications
Medications such as labetalol, methyldopa, and nifedipine are generally considered safe and effective for controlling hypertension in pregnancy.
Angiotensin-Converting Enzyme inhibitors and Angiotensin II Receptor Blockers should be strictly avoided as they can harm the developing fetus.
Lifestyle adjustments such as bed rest, support medical treatment.
Close follow-up with a healthcare provider ensures timely adjustments in medication and monitoring of the mother's and baby's health.

Introduction

High blood pressure (hypertension) in pregnancy means your blood pressure is ≥140/90 mmHg or above on repeated measurements. Monitoring this condition during pregnancy is important because it can affect both the mother’s health and the baby’s growth and development. It can appear before pregnancy (chronic) or develop during pregnancy (gestational hypertension or preeclampsia).

Why Hypertension in Pregnancy Matters

Hypertension in pregnancy matters because it can affect your health and that of your baby, leading to serious complications if not properly managed.

Risks for the Mother
- May require early delivery (C-section or induction).
- May lead to seizures (eclampsia).
- Untreated hypertension increases the risk of early separation of the placenta from the uterus before childbirth, causing bleeding and risk to both mother and baby.
- May cause long-term cardiovascular disease in mothers
- Can cause organ damage, especially to the kidneys, liver, and brain.
- Increases the risk of postpartum hypertension.
- May lead to HELLP syndrome (Hemolysis, Elevated Liver enzymes, Low Platelet count).
- Can result in stroke or heart failure due to severely raised high blood pressure.
Risks for the Baby
- Reduced blood flow to the placenta → less oxygen and nutrients.
- Risk of intrauterine growth retardation (IUGR) → low birth weight.
- Higher chances of preterm birth or even stillbirth in severe cases.
- Babies may require a Neonatal Intensive Care Unit (NICU) admission if born early or underweight

Types of Hypertension in Pregnancy

During pregnancy, blood pressure changes are closely monitored because elevated readings can indicate different forms of hypertension, each carrying its own risks for you and the babyUnderstanding the types of hypertension in pregnancy is important for early diagnosis, proper management, and safe outcomes.The following are the types of hypertension in pregnancy: [1]

1. Chronic Hypertension

Chronic hypertension is diagnosed before pregnancy or before 20 weeks of gestation
May continue even after delivery.

2. Gestational Hypertension

High blood pressure that develops after the 20th week of pregnancy.
No protein in urine or organ damage (unlike preeclampsia).
Usually resolves after birth, but some women may develop chronic hypertension later.
Monitoring blood pressure regularly during prenatal visits helps detect these conditions early

3. Preeclampsia

High blood pressure after 20 weeks of pregnancy, plus signs of organ involvement (e.g., protein in urine, liver or kidney dysfunction, low platelets).
It can be mild or severe.
Serious complications if not managed properly.

4. Eclampsia

Severe form of preeclampsia where seizures occur.
Medical emergency, dangerous for both mother and baby.

5. Chronic Hypertension with Superimposed Preeclampsia

Women who already have chronic hypertension but then develop preeclampsia (new proteinuria or organ problems during pregnancy).
Higher risk of complications.

It is important to note that diagnosis often requires multiple readings and sometimes laboratory evaluation, such as urine protein, liver enzymes, and platelets.

Drugs Commonly Used to Treat Hypertension in Pregnancy

Drugs commonly used to treat hypertension in pregnancy are: [2]

1. Methyldopa

One of the safest and most widely used drugs in pregnancy.
Works by relaxing blood vessels through its action on the brain and nerves that control blood pressure.
Often used for long-term control, though less effective in severe cases.
Route: Oral (tablet) or intravenous (less common).
Typical dosage: 250 mg to 500 mg taken two to three times daily (maximum up to 2 grams per day, as prescribed by the doctor).

2. Labetalol

Labetalol, a beta-blocker, lowers blood pressure by slowing the heart and relaxing blood vessels.
Commonly used in both mild and severe hypertension during pregnancy.

Route: Taken by mouth (tablet) or given through a vein (IV) in the hospital for severe cases.

Typical dosage:

Oral: Treatment usually starts with 20 mg of labetalol, the dose can be increased every 10 minutes by 20–40 mg, up to a single dose of 80 mg, and a total of 300 mg should not be exceeded.

IV (in hospital): It usually starts with 10–20 mg, which can be repeated every 10 minutes until the blood pressure improves, not exceeding 300 mg in 24 hours.

If needed, it can also be given as a slow drip starting at 0.5–2 mg per minute, and increasing up to 10 mg per minute.

3. Nifedipine

Nifedipine, a calcium channel blocker, works by relaxing and widening the blood vessels, which allows blood to flow more easily and helps lower blood pressure.
Can be used orally for both acute and chronic hypertension in pregnancy.

Route: Taken by mouth (tablet or capsule).

Typical dosage:

Immediate-release: 10–20 mg may be repeated every 30–60 minutes if needed (for emergency control, under doctor’s supervision).
Extended-release: 30–60 mg once daily (can be increased up to 120 mg per day as prescribed).

4. Hydralazine

Hydralazine, a vasodilator, works by relaxing the muscles in the walls of blood vessels, which helps them widen, allowing blood to flow more easily and lowering blood pressure.
Often used in emergencies (e.g., severe hypertension, preeclampsia).
Given intravenously or intramuscularly for rapid control.

Route: Given through a vein (IV) or sometimes by injection into a muscle (IM).

Typical dosage:

IV: 10 mg slow injection, may be repeated every 20–30 minutes if needed (maximum 20 mg per dose).

Hypertension Drugs to Avoid when Pregnant

Angiotensin-Converting Enzyme (ACE) inhibitors (e.g., enalapril)
Angiotensin II Receptor Blockers (ARBs) (e.g., losartan)
Direct Renin Inhibitors (e.g., Aliskiren)

These drugs are avoided because they can harm your baby(kidney damage, growth restriction, or even fetal death).

The Definitive Cure

In preeclampsia, eclampsia and gestational hypertension, the root cause of the problem lies in the placenta. The placenta does not develop or function normally, which leads to abnormal blood vessel behaviour, causing high blood pressure and damage to organs like the liver and kidneys [3].

Because the placenta is the main source of the disease process, the only way to completely stop the progression of preeclampsia is to deliver the baby and remove the placenta. This is why delivery is considered the definitive (curative) treatment [3].

However, if your pregnancy is too early, immediate delivery may put the baby at risk due to prematurity. In such cases, medications are used temporarily to:

Control your blood pressure,
Prevent seizures (with drugs like magnesium sulphate),
Get time to allow the baby’s lungs to mature before delivery.

When Hypertension Drugs Are Used

Your doctor would recommend antihypertensive drugs when: [4]

Systolic blood pressure ≥150 mmHg or diastolic blood pressure ≥100 mmHg, measured persistently.
Severe hypertension ≥160/110 mmHg is present, and immediate treatment is required to prevent maternal stroke, heart failure, or placental abruption.
Blood pressure control is needed to stabilise the mother before delivery or to allow time for the fetus to get mature (e.g., while corticosteroids are given to enhance lung maturity).
Blood pressure rises during labour, caesarean section, or the postpartum period, requiring short-term control.

Purpose of Hypertensive Medication

To prevent maternal complications such as brain and kidney damage, or eclampsia.
To maintain placental blood flow, ensuring better oxygen and nutrient supply to the fetus.
To buy time allowing the pregnancy to continue safely for a few more days or weeks if immediate delivery poses neonatal risks.

Key Principle

Delivery of the baby and placenta remains the only definitive cure for preeclampsia and pregnancy-related hypertension.
Antihypertensive drugs act as supportive therapy to manage blood pressure until the timing of delivery becomes optimal.

When to Seek Urgent Care

If you have high blood pressure or preeclampsia, you should seek immediate medical attention if you experience any of the following warning signs. These symptoms may indicate that the condition is worsening or that serious complications are developing for the mother or baby [5].

1. Severe or Persistent Headache

A strong, throbbing headache that doesn’t improve with rest or pain relief may indicate very high blood pressure or impending eclampsia (risk of seizures).

2. Vision Changes

Blurred vision, flashing lights, double vision, or temporary loss of vision suggest brain or retinal involvement due to severe hypertension, a warning of possible seizures or stroke.

3. Sudden Swelling

Rapid or excessive swelling of the face, hands, feet, or around the eyes (oedema) may signal fluid retention and worsening preeclampsia.

4. Chest Pain or Shortness of Breath

These may be signs of fluid buildup in the lungs (pulmonary oedema) or cardiac strain, both of which are potentially life-threatening.

5. Reduced or Absent Baby Movements

A noticeable decrease in the baby’s movements may indicate fetal distress or reduced placental blood flow, requiring urgent assessment.

Conclusion

Managing high blood pressure during pregnancy is essential to protect both the mother and the baby from serious complications such as preeclampsia, preterm birth, or organ damage. Commonly prescribed drugs such as labetalol, methyldopa, and nifedipine are considered safe and effective for most pregnant women. It’s important to avoid medications that can harm the baby, such as ACE inhibitors and ARBs. Regular prenatal monitoring, adherence to prescribed treatment, and open communication with healthcare providers are key to ensuring a healthy pregnancy and delivery.

References

Apurva M Khedagi, Natalie A Bello. Hypertensive Disorders of Pregnancy. Cardiol Clin. 2020 Nov 2;39(1):77–90. Available from:

https://pmc.ncbi.nlm.nih.gov/articles/PMC7720658/

Amanda Beech, George Mangos. Management of hypertension in pregnancy. Aust Prescr. 2021 Oct 1;44(5):148–152. Available from:

https://pmc.ncbi.nlm.nih.gov/articles/PMC8542489/

Dhruvikumari D Sharma, Nidhi R Chandresh, Ayesha Javed, Peter Girgis, Madiha Zeeshan, Syeda Simrah Fatima, Taneen T Arab, Sreeja Gopidasan, Vineesha Chowdary Daddala, Kalgi V Vaghasiya, Ameena Soofia, Maneeth Mylavarapu. The Management of Preeclampsia: A Comprehensive Review of Current Practices and Future Directions. Cureus. 2024 Jan 2;16(1):e51512. Available from:https://pmc.ncbi.nlm.nih.gov/articles/PMC10832549/

Richard K. Luger; Benjamin P. Kight. Hypertension In Pregnancy. In: StatPearls [Internet]. StatPearls Publishing; Last Update: October 3, 2022. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430839/

Shahd A. Karrar; Daniel J. Martingano; Peter L. Hong. Preeclampsia. In: StatPearls [Internet]. StatPearls Publishing; Last Update: February 25, 2024. Available from:https://www.ncbi.nlm.nih.gov/books/NBK570611/

Disclaimer:
The information provided on this website is for general educational and informational purposes only. It is not intended to replace professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

Published October 24, 2025

A black pregnant woman sitting with a doctor in red scrubs and a white ward coat checking her blood pressure

Drugs for High Blood Pressure in Pregnancy: What You Need to Know

Highlights

Introduction

Why Hypertension in Pregnancy Matters

Risks for the Mother

Risks for the Baby

Types of Hypertension in Pregnancy

1. Chronic Hypertension

2. Gestational Hypertension

3. Preeclampsia

4. Eclampsia

5. Chronic Hypertension with Superimposed Preeclampsia

Drugs Commonly Used to Treat Hypertension in Pregnancy

1. Methyldopa

One of the safest and most widely used drugs in pregnancy.

Works by relaxing blood vessels through its action on the brain and nerves that control blood pressure.

Often used for long-term control, though less effective in severe cases.

Route: Oral (tablet) or intravenous (less common).

Typical dosage: 250 mg to 500 mg taken two to three times daily (maximum up to 2 grams per day, as prescribed by the doctor).

2. Labetalol

Labetalol, a beta-blocker, lowers blood pressure by slowing the heart and relaxing blood vessels.

Commonly used in both mild and severe hypertension during pregnancy.

Route: Taken by mouth (tablet) or given through a vein (IV) in the hospital for severe cases.

Typical dosage:

Oral: Treatment usually starts with 20 mg of labetalol, the dose can be increased every 10 minutes by 20–40 mg, up to a single dose of 80 mg, and a total of 300 mg should not be exceeded.

IV (in hospital): It usually starts with 10–20 mg, which can be repeated every 10 minutes until the blood pressure improves, not exceeding 300 mg in 24 hours.

If needed, it can also be given as a slow drip starting at 0.5–2 mg per minute, and increasing up to 10 mg per minute.

3. Nifedipine

Nifedipine, a calcium channel blocker, works by relaxing and widening the blood vessels, which allows blood to flow more easily and helps lower blood pressure.

Can be used orally for both acute and chronic hypertension in pregnancy.

Route: Taken by mouth (tablet or capsule).

Typical dosage:

Immediate-release: 10–20 mg may be repeated every 30–60 minutes if needed (for emergency control, under doctor’s supervision).

Extended-release: 30–60 mg once daily (can be increased up to 120 mg per day as prescribed).

4. Hydralazine

Hydralazine, a vasodilator, works by relaxing the muscles in the walls of blood vessels, which helps them widen, allowing blood to flow more easily and lowering blood pressure.

Often used in emergencies (e.g., severe hypertension, preeclampsia).

Given intravenously or intramuscularly for rapid control.

Route: Given through a vein (IV) or sometimes by injection into a muscle (IM).

Typical dosage:

IV: 10 mg slow injection, may be repeated every 20–30 minutes if needed (maximum 20 mg per dose).

Hypertension Drugs to Avoid when Pregnant

Angiotensin-Converting Enzyme (ACE) inhibitors (e.g., enalapril)

Angiotensin II Receptor Blockers (ARBs) (e.g., losartan)

Direct Renin Inhibitors (e.g., Aliskiren)

These drugs are avoided because they can harm your baby(kidney damage, growth restriction, or even fetal death).

The Definitive Cure

In preeclampsia, eclampsia and gestational hypertension, the root cause of the problem lies in the placenta. The placenta does not develop or function normally, which leads to abnormal blood vessel behaviour, causing high blood pressure and damage to organs like the liver and kidneys [3].

Because the placenta is the main source of the disease process, the only way to completely stop the progression of preeclampsia is to deliver the baby and remove the placenta. This is why delivery is considered the definitive (curative) treatment [3].

However, if your pregnancy is too early, immediate delivery may put the baby at risk due to prematurity. In such cases, medications are used temporarily to:

Control your blood pressure,

Prevent seizures (with drugs like magnesium sulphate),

Get time to allow the baby’s lungs to mature before delivery.

When Hypertension Drugs Are Used

Your doctor would recommend antihypertensive drugs when: [4]

Systolic blood pressure ≥150 mmHg or diastolic blood pressure ≥100 mmHg, measured persistently.

Severe hypertension ≥160/110 mmHg is present, and immediate treatment is required to prevent maternal stroke, heart failure, or placental abruption.

Blood pressure control is needed to stabilise the mother before delivery or to allow time for the fetus to get mature (e.g., while corticosteroids are given to enhance lung maturity).

Blood pressure rises during labour, caesarean section, or the postpartum period, requiring short-term control.

Purpose of Hypertensive Medication

To prevent maternal complications such as brain and kidney damage, or eclampsia.

To maintain placental blood flow, ensuring better oxygen and nutrient supply to the fetus.

To buy time allowing the pregnancy to continue safely for a few more days or weeks if immediate delivery poses neonatal risks.

Key Principle

When to Seek Urgent Care

1. Severe or Persistent Headache

A strong, throbbing headache that doesn’t improve with rest or pain relief may indicate very high blood pressure or impending eclampsia (risk of seizures).

2. Vision Changes

Blurred vision, flashing lights, double vision, or temporary loss of vision suggest brain or retinal involvement due to severe hypertension, a warning of possible seizures or stroke.

3. Sudden Swelling

Rapid or excessive swelling of the face, hands, feet, or around the eyes (oedema) may signal fluid retention and worsening preeclampsia.

4. Chest Pain or Shortness of Breath

These may be signs of fluid buildup in the lungs (pulmonary oedema) or cardiac strain, both of which are potentially life-threatening.

5. Reduced or Absent Baby Movements

A noticeable decrease in the baby’s movements may indicate fetal distress or reduced placental blood flow, requiring urgent assessment.

Conclusion

References