Understanding High Blood Pressure During Pregnancy: A Guide for Expectant Mothers

This guide explains the different types of high blood pressure during pregnancy, including gestational hypertension and preeclampsia. Learn about symptoms, risk factors, diagnosis, treatment, and what to expect for your health and your baby's well-being.

Published: October 27, 2023•Updated: October 27, 2023

Understanding High Blood Pressure During Pregnancy

Pregnancy is a beautiful journey, but sometimes health challenges can arise. One common concern is high blood pressure, also known as hypertension, which can develop or worsen during pregnancy. This guide from Param Maternity & Surgical Nursing Home is designed to help you understand what high blood pressure in pregnancy means for you and your baby, how it's managed, and what you can do to stay healthy.

It's important to remember that this information is for educational purposes and should not replace the advice of your doctor or healthcare team. Always discuss your specific health concerns with a medical professional.

What is High Blood Pressure in Pregnancy?

High blood pressure during pregnancy refers to a group of conditions where your blood pressure becomes elevated. Your healthcare provider will classify your condition based on when it starts and whether other signs of organ stress are present. Here are the main types:

Chronic Hypertension: This means you had high blood pressure before pregnancy, or it was diagnosed before 20 weeks of gestation. It can also be diagnosed during pregnancy and continues for more than 12 weeks after delivery.
Gestational Hypertension: This is new high blood pressure (typically 140/90 mmHg or higher) that develops after 20 weeks of pregnancy. Importantly, there are no other signs of organ damage, and your blood pressure usually returns to normal within 12 weeks after birth.
Preeclampsia: This is a more serious condition where new high blood pressure (140/90 mmHg or higher) develops after 20 weeks of pregnancy, along with signs of organ damage. This might include protein in your urine (proteinuria) or other issues like low platelet count, kidney problems, liver problems, fluid in your lungs, or new, persistent headaches or vision changes.
Preeclampsia with Severe Features: This is preeclampsia with very high blood pressure (160/110 mmHg or higher) or more pronounced signs of organ damage, such as very low platelets, significant kidney or liver issues, severe lung fluid, or persistent neurological symptoms.
Eclampsia: This is the most severe form of preeclampsia, characterized by new-onset seizures that cannot be attributed to other causes. It's a medical emergency.
HELLP Syndrome: A rare but very serious variant of preeclampsia. HELLP stands for Hemolysis (breakdown of red blood cells), Elevated Liver enzymes, and Low Platelet count.
Chronic Hypertension with Superimposed Preeclampsia: This occurs when a woman who already has chronic high blood pressure develops new signs of preeclampsia.

You might hear older terms like 'Pregnancy-Induced Hypertension (PIH)' or 'Toxemia,' but these are less precise and generally not used by healthcare professionals today. Your doctor will use the specific classifications above to guide your care. ^{1, ²}

What Causes High Blood Pressure in Pregnancy?

The exact cause of preeclampsia and other hypertensive disorders of pregnancy isn't fully known, but we understand a lot about how it develops. It's thought to be a two-stage process:

Placental Development: Early in pregnancy, there can be issues with how the placenta's blood vessels develop. This can lead to reduced blood flow to the placenta.
Maternal Response: The placenta, when not functioning optimally, can release certain substances into your bloodstream. These substances can affect your blood vessels throughout your body, leading to high blood pressure, protein in your urine, and other symptoms.

Factors like abnormal placental development, issues with your immune system's response to the pregnancy, and even your genes can play a role. ⁴

Who is at Risk for High Blood Pressure in Pregnancy?

While anyone can develop high blood pressure during pregnancy, certain factors can increase your risk. Your doctor will assess these to understand your individual risk profile.

High-Risk Factors (one or more indicates high risk):

A history of preeclampsia in a previous pregnancy, especially if it was severe.
Carrying multiple babies (like twins or triplets).
Having chronic high blood pressure before pregnancy.
Having Type 1 or Type 2 diabetes.
Having kidney disease.
Having an autoimmune disease (like lupus or antiphospholipid syndrome).

Moderate-Risk Factors (two or more indicates high risk):

This is your first pregnancy.
Obesity (Body Mass Index over 30 kg/m²).
A family history of preeclampsia (your mother or sister had it).
Being 35 years old or older.
A long gap (more than 10 years) between pregnancies.
Pregnancy conceived through in vitro fertilization (IVF).

Some risk factors, like obesity or poorly controlled pre-existing conditions, can be managed before or during pregnancy. Others, like your age or family history, cannot be changed. ³

Recognizing the Signs: Symptoms to Watch For

It's important to know that many women with gestational hypertension or mild preeclampsia might not feel any symptoms at all. This is why regular prenatal check-ups are so important!

Common Symptoms (may or may not indicate a problem):

Swelling (edema): Especially in your hands, face, or feet. While common in normal pregnancy, sudden or severe swelling can be a sign.
Headache: Mild to moderate.
Rapid weight gain: More than 2 pounds (about 1 kg) in a week.

Emergency / Red Flag Symptoms (Call your doctor immediately if you experience any of these):

These symptoms can indicate a more severe form of preeclampsia and require urgent medical attention:

Severe headache: Often described as persistent, throbbing, and not relieved by common pain relievers.
Vision changes: Blurred vision, seeing flashing lights or spots, or temporary loss of vision.
Severe pain in your upper abdomen: Typically on the right side, under your ribs, or in the pit of your stomach. This can be a sign of liver issues.
Shortness of breath: Difficulty breathing, which could be due to fluid in your lungs.
Decreased urine output: Not urinating as much as usual.
Altered mental status: Feeling confused or unusually anxious.

If you experience any of these red flag symptoms, do not wait. Contact your healthcare provider or go to the nearest emergency room right away. ⁵

How is High Blood Pressure Diagnosed?

Diagnosing high blood pressure in pregnancy involves a combination of your medical history, physical exams, and laboratory tests.

History: Your doctor will ask about your medical background, any previous pregnancies, and family history of high blood pressure.
Physical Examination: The most crucial part is accurate blood pressure measurement. Your blood pressure will be checked at every prenatal visit. For a diagnosis, your doctor will look for sustained high readings (140/90 mmHg or higher) on two occasions, usually at least four hours apart. They will also check for swelling and may assess your reflexes.
Laboratory Tests:
- Urine tests: To check for protein in your urine (proteinuria), which is a key sign of preeclampsia.
- Blood tests: To check your platelet count (for thrombocytopenia), liver function (for elevated enzymes), and kidney function (for serum creatinine levels).
Obstetric Ultrasound: An ultrasound may be used to check your baby's growth, the amount of amniotic fluid, and blood flow through the umbilical cord.

Regular blood pressure checks and sometimes urine tests are part of routine prenatal care to catch any issues early. ^{1, ⁶}

Managing High Blood Pressure in Pregnancy

The management plan for high blood pressure in pregnancy depends on the specific diagnosis, the severity of your condition, and your baby's gestational age.

Lifestyle Adjustments:

Activity: While rest is important, strict bed rest is generally not recommended as it can increase other risks. Your doctor will advise on appropriate activity levels.
Diet: A balanced, healthy diet is always recommended. There's no specific diet (like salt restriction) proven to treat or prevent preeclampsia.

Medical Treatment:

Blood Pressure Medications: If your blood pressure is consistently high (140/90 mmHg or higher), your doctor may prescribe medication to lower it. The goal is to prevent serious complications for you, like stroke. Medications commonly used include Labetalol, Nifedipine, and Methyldopa. Certain medications, like ACE inhibitors, are not safe during pregnancy.
Magnesium Sulfate: For women with preeclampsia with severe features or eclampsia, magnesium sulfate is given intravenously to prevent or treat seizures. It's usually given during labor and for 24 hours after delivery.

The Definitive Treatment: Delivery

The only true cure for preeclampsia is the delivery of the placenta. The timing of delivery is a careful decision made by your healthcare team, balancing your health and your baby's development:

For gestational hypertension or preeclampsia without severe features, delivery is often recommended around 37 weeks of pregnancy.
For preeclampsia with severe features, delivery may be recommended as early as 34 weeks, or even earlier if your or your baby's condition worsens.

In some cases of severe preeclampsia diagnosed before 34 weeks, if both you and your baby are stable, your doctor might consider 'expectant management' in a specialized hospital setting to allow your baby more time to grow. ⁷

Emergency Situations:

If you develop very high blood pressure (hypertensive crisis) or eclampsia (seizures), immediate medical treatment is necessary to stabilize your condition before delivery.

Postpartum Follow-up:

Your blood pressure will be closely monitored after delivery, as complications can still occur. You'll likely have your blood pressure checked in the hospital for at least 72 hours and again 7-10 days after going home. ⁸

Potential Complications

High blood pressure during pregnancy can lead to complications for both you and your baby. Early detection and careful management help reduce these risks.

For the Mother (Short-Term):

Eclampsia (seizures)
HELLP syndrome
Placental abruption (when the placenta separates from the uterus too early)
Stroke
Fluid in the lungs (pulmonary edema)
Kidney failure
Blood clotting problems (DIC)
In rare cases, maternal death

For the Mother (Long-Term):

Increased risk of developing chronic high blood pressure, heart disease, and stroke later in life.
Increased risk of type 2 diabetes.
Increased risk of kidney disease.

For the Baby:

Fetal growth restriction (baby doesn't grow as expected)
Low amniotic fluid (oligohydramnios)
Preterm birth (being born too early)
Low birth weight
Breathing difficulties at birth
Stillbirth (in severe cases)

Because of these long-term risks, women who have had preeclampsia are encouraged to discuss their health history with their primary care doctor for ongoing monitoring. ^{9, ¹⁰}

Can High Blood Pressure in Pregnancy be Prevented?

While there's no guaranteed way to prevent all cases of high blood pressure in pregnancy, especially preeclampsia, there are strategies to reduce your risk, particularly if you have certain risk factors.

Before Pregnancy:

Aim for a healthy weight.
Manage any existing conditions like chronic high blood pressure or diabetes.

During Pregnancy (Secondary Prevention):

Low-Dose Aspirin: If you are at high risk for preeclampsia (based on the factors mentioned earlier), your doctor may recommend taking low-dose aspirin (typically 81 mg daily) starting between 12 and 28 weeks of pregnancy (ideally before 16 weeks) and continuing until delivery. ¹¹
Calcium Supplementation: In areas where women may not get enough calcium from their diet, calcium supplements (1.5–2.0 g elemental calcium per day) are recommended for all pregnant women, especially those at higher risk for preeclampsia. This is not routinely recommended if your diet provides adequate calcium. ¹²

Regular prenatal care, including blood pressure checks and urine tests, is crucial for early detection and management. ¹

What to Expect Long-Term: Prognosis

For most women, high blood pressure conditions in pregnancy resolve after the baby is born and the placenta is delivered. Your blood pressure usually returns to normal within 12 weeks postpartum. If it remains high, you may be diagnosed with chronic hypertension.

Recurrence Risk:

If you've had preeclampsia in one pregnancy, your risk of it happening again in a future pregnancy is higher. It's approximately 15-20% after one previous preeclampsia pregnancy and can be higher (30-40%) if your previous preeclampsia was severe or started early. ¹

Long-Term Health:

A history of preeclampsia is now recognized as a risk factor for future cardiovascular disease. This means you have a higher chance of developing chronic high blood pressure, heart disease, or stroke later in life. It's important to discuss this with your primary care doctor for ongoing health monitoring and to adopt a heart-healthy lifestyle. ¹⁰

When to Contact Your Doctor

Your healthcare team at Param Maternity & Surgical Nursing Home is here to support you throughout your pregnancy. Always contact your doctor or midwife if you have any concerns about your blood pressure or experience any of the following symptoms:

A blood pressure reading of 140/90 mmHg or higher, even if you feel fine.
Severe, persistent headache not relieved by medication.
Changes in your vision (blurred vision, flashing lights, spots).
Severe pain in your upper abdomen (under your ribs on the right side).
Sudden swelling in your face, hands, or feet.
Shortness of breath.
Decreased urine output.
Any new or worsening symptoms that concern you.

Early communication and prompt medical attention are key to ensuring the best possible outcomes for both you and your baby.

Frequently Asked Questions

What blood pressure reading is considered high during pregnancy?

A blood pressure reading of 140/90 mmHg or higher is generally considered high during pregnancy. Your doctor will look for sustained readings at this level or above on two occasions, usually at least four hours apart, to make a diagnosis.

What is the difference between gestational hypertension and preeclampsia?

Gestational hypertension is new high blood pressure (140/90 mmHg or higher) that develops after 20 weeks of pregnancy, without any other signs of organ damage. Preeclampsia also involves new high blood pressure after 20 weeks, but it includes signs of organ damage, such as protein in your urine, low platelet count, kidney or liver problems, or severe headaches/vision changes.

If I have high blood pressure, does it automatically mean I have preeclampsia?

No, not automatically. You could have gestational hypertension, which is high blood pressure without other signs of organ damage. Preeclampsia is diagnosed when high blood pressure is accompanied by specific signs of organ involvement. Your doctor will perform tests to determine the exact diagnosis.

What are the warning signs of preeclampsia I should watch for?

Key warning signs include severe, persistent headache not relieved by medication; changes in vision (blurred vision, flashing lights, spots); severe pain in your upper abdomen (under your ribs on the right side); shortness of breath; decreased urine output; and sudden, significant swelling in your face or hands. Contact your doctor immediately if you experience any of these.

Is swelling in my feet and hands a definite sign of a problem?

Swelling (edema) in the feet and hands is common in normal pregnancy. However, sudden, severe, or generalized swelling, especially in the face, can be a sign of preeclampsia. It's important to mention any new or worsening swelling to your doctor, but it's no longer a primary diagnostic criterion for preeclampsia on its own.

Will I need to be on medication for my blood pressure?

If your blood pressure is consistently 140/90 mmHg or higher, your doctor may recommend medication to help control it and prevent complications. The decision depends on your specific blood pressure readings, your overall health, and the type of high blood pressure you have.

Are blood pressure medications safe for my baby?

Yes, if medication is prescribed, your doctor will choose options that are known to be safe for use during pregnancy and breastfeeding. It's crucial to take your medication exactly as prescribed and discuss any concerns with your healthcare provider.

What is low-dose aspirin used for, and should I be taking it?

Low-dose aspirin (typically 81 mg daily) is recommended for pregnant individuals at high risk of developing preeclampsia. If you have certain risk factors, your doctor may advise you to start taking it between 12 and 28 weeks of pregnancy to help reduce your risk. Do not start aspirin without your doctor's recommendation.

Will I need to be on bed rest?

Strict bed rest is generally not recommended for high blood pressure in pregnancy, as it hasn't been shown to improve outcomes and can increase other risks like blood clots. Your doctor will advise on appropriate activity levels based on your condition.

How will high blood pressure affect my baby's growth?

High blood pressure, especially preeclampsia, can sometimes affect the placenta's ability to deliver nutrients and oxygen to your baby. This can lead to slower growth (fetal growth restriction) or your baby being born smaller than expected. Your doctor will monitor your baby's growth closely with ultrasounds.

Will I need to be induced early or have a C-section?

The timing and method of delivery depend on the type and severity of your high blood pressure, your baby's health, and your gestational age. For some conditions, early delivery (induction or C-section) may be recommended to protect your health and your baby's well-being. Your doctor will discuss the best plan for you.

What is HELLP syndrome?

HELLP syndrome is a rare but very serious complication of preeclampsia. It stands for Hemolysis (breakdown of red blood cells), Elevated Liver enzymes, and Low Platelet count. It requires immediate medical attention.

What is eclampsia?

Eclampsia is the most severe form of preeclampsia, characterized by new-onset seizures in a woman with preeclampsia that cannot be attributed to other causes. It is a medical emergency.

How is preeclampsia monitored?

Preeclampsia is monitored through regular blood pressure checks, urine tests for protein, blood tests to check kidney and liver function and platelet count, and ultrasounds to monitor your baby's growth and well-being. You may also be asked to monitor your symptoms closely.

Can preeclampsia develop after I give birth?

Yes, preeclampsia can develop or worsen in the postpartum period, typically within the first few days to weeks after delivery. This is why close monitoring of your blood pressure and symptoms is crucial after birth.

If I had preeclampsia in one pregnancy, will I get it again?

Having preeclampsia in a previous pregnancy increases your risk of developing it again in future pregnancies. The risk is higher if your previous preeclampsia was severe or started early. Your doctor will discuss your individual recurrence risk and preventive strategies.

Can I do anything with my diet to prevent or treat high blood pressure in pregnancy?

While a healthy, balanced diet is always recommended during pregnancy, there's no specific diet (like salt restriction) proven to prevent or treat high blood pressure conditions like preeclampsia. However, if you live in an area with low dietary calcium intake, your doctor might recommend calcium supplementation.

Does having preeclampsia mean I will have high blood pressure for the rest of my life?

Not necessarily. For most women, blood pressure returns to normal within 12 weeks after delivery. However, having preeclampsia does increase your long-term risk of developing chronic high blood pressure and other cardiovascular diseases later in life. It's important to have regular check-ups with your primary care doctor.

What are the long-term health risks associated with having preeclampsia?

Women with a history of preeclampsia have an increased risk of developing chronic high blood pressure, heart disease (like ischemic heart disease), stroke, and type 2 diabetes later in life. It's important to discuss this with your doctor for ongoing health monitoring and lifestyle advice.

Can I breastfeed if I am on blood pressure medication after delivery?

Many blood pressure medications are safe to use while breastfeeding. Your doctor will prescribe medications that are compatible with breastfeeding or advise you on the best course of action to ensure both your health and your baby's safety.

How soon after delivery will my blood pressure return to normal?

For most women, blood pressure typically returns to normal within 12 weeks after delivery. However, it's crucial to continue monitoring your blood pressure during the postpartum period, as complications can still arise, and some women may develop chronic hypertension.

What kind of follow-up care will I need after a hypertensive pregnancy?

You will need close blood pressure monitoring in the hospital for at least 72 hours after delivery and again 7-10 days postpartum. Your doctor will also recommend long-term follow-up with your primary care physician to monitor your cardiovascular health, given the increased risk of future conditions like chronic hypertension and heart disease.

Understanding High Blood Pressure During Pregnancy: A Guide for Expectant Mothers