Preeclampsia: High Blood Pressure During Pregnancy

High blood pressure during pregnancy, or preeclampsia, affects 7 out of every 100 pregnant women. It affects most of these women during their first pregnancy. High blood pressure occurs when the pressure of the blood inside the arteries builds up to levels that are greater than normal.

High blood pressure during pregnancy, or preeclampsia, is a condition that affects some pregnant women. High blood pressure occurs when the blood pressure in the arteries builds up to levels greater than normal.

What is preeclampsia?

Preeclampsia is a multisystem progressive disorder characterised by the new onset of hypertension and proteinuria or the new onset of hypertension plus significant end-organ dysfunction with or without proteinuria, typically presenting after 20 weeks of gestation or postpartum.

Preeclampsia usually begins after 20 weeks of pregnancy in women whose blood pressure was previously normal. Preeclampsia can lead to severe complications for both mother and baby. For the baby, it can reduce the amount of the mother's blood flow to the placenta, causing the baby's growth to be restricted.

Early delivery of the baby is often recommended. Before delivery, preeclampsia treatment includes careful monitoring and medications to lower blood pressure.

What causes preeclampsia?

The cause of preeclampsia is unknown. Most women newly diagnosed with preeclampsia were not previously known to have high blood pressure (hypertension). The pathogenesis of preeclampsia likely involves both placental and maternal factors. Abnormal development of the placental vasculature early in pregnancy (failure of normal spiral artery remodeling) is a key event that results in relative placental underperfusion, hypoxia, ischemia, and oxidative stress, leading to release of antiangiogenic factors into the maternal circulation. These factors can cause widespread maternal systemic endothelial dysfunction, eventually resulting in the clinical manifestations of the disease.

However, the following may play a role:

Abnormalities in the development of the placenta early in pregnancy: If the placenta does not infiltrate sufficiently deep into the uterus and establish a healthy blood supply from the mother, it may not be able to provide appropriate nutrients and oxygen to the foetus or itself as the pregnancy continues. During the initial stages of pregnancy, the embryo produces root-like growths called villi that help anchor it to the uterus lining. These villi are fed nutrients through blood vessels in the womb, which normally widen to support the growing placenta better. However, if these blood vessels don’t fully transform, the placenta may not develop properly due to insufficient nutrient intake, potentially leading to preeclampsia.
Genetic predisposition also plays a role in the development of preeclampsia. Inherited changes in your genes likely have some sort of role, as the condition often runs in families. However, this only explains some cases, as the exact reason why the blood vessels fail to transform properly remains to be seen.

How Preeclampsia is Diagnosed?

Pre-eclampsia can be easily detected during routine antenatal appointments. At these checkups, your blood pressure is monitored, and a urine sample is tested for protein, which can indicate pre-eclampsia.

You will need to monitor the signs and symptoms of preeclampsia during your pregnancy:

Blood Pressure

Blood pressure measures the force of blood on artery walls. It’s recorded as systolic (when the heart beats) and diastolic (when the heart rests). High blood pressure in pregnancy is 140/90 mmHg or higher.

Urine Test

A dipstick test at each antenatal appointment checks for protein in your urine, which can signal pre-eclampsia.

Hospital Tests

If diagnosed with pre-eclampsia, you’ll be referred to the O&G specialist for further and closer monitoring. In severe cases, a hospital stay may be necessary, and if the symptoms do not improve with treatment, prompt delivery may be advised.

What are the risk factors for preeclampsia?

Several factors have been identified as risk factors for preeclampsia, and they include:

First pregnancy (excluding abortions and miscarriages)
Chronic high blood pressure or kidney disease before pregnancy
High blood pressure or preeclampsia in an earlier pregnancy
Obesity
Women older than 40 are at higher risk
Multiple gestations (twins or triplets)
Family history of preeclampsia
Pregnancies with donor insemination or in-vitro fertilisation (IVF)
Age >40 years or <18 years
Diabetes
Autoimmune disease
Fetal growth restriction
Different partner

If you are at high risk for preeclampsia, healthcare professionals may recommend taking a daily aspirin dose of 75mg to 150mg, starting at 12 weeks of pregnancy and continuing until your baby's birth.

What are the symptoms of preeclampsia?

Many women with preeclampsia do not have distinct symptoms of hypertension and may not be aware of the condition. Therefore, prenatal visits to screen for hypertension are scheduled frequently.

Preeclampsia Symptoms include:

Sudden weight gain
Swelling of the face or fingers
Headaches
Blurred vision or seeing spots
Pain in the upper abdomen
Nausea or vomiting

Signs of severe preeclampsia include:

Abdominal pain
Impaired liver or kidney function
Seizures
Fluid in the lungs causing difficulty in breathing
Changes in baby's heart rate, indicating fetal distress

Women with preeclampsia are also likely to present with protein in their urine, abnormal liver enzymes and low platelet levels. Hence, your doctor would request urine and blood tests to look for these signs.

What are the complications of preeclampsia?

Preeclampsia, if left untreated, may cause complications for the baby in the womb, such as:

Fetal growth restriction
Premature delivery
Stillborn

Extremely high levels of blood pressure in the mother that persist without medical care can damage organs, such as the kidneys, brain, eyes, and liver.

HELLP Syndrome

HELLP Syndrome is a rare disorder that occurs when there is damage to the liver and blood cells. It is a medical emergency characterised by:

H: Haemolysis, where red blood cells that function to carry oxygen throughout your body break down
EL: Elevated liver enzymes indicate liver damage
LP: Low platelet count. Platelets help blood clot

The primary treatment for HELLP Syndrome is to deliver the baby as soon as feasible. With prompt hospitalization and treatment, the mother has a strong possibility of making a full recovery.

Eclampsia

If the blood pressure rises to very high levels and persists, seizures or fits can occur. However, eclampsia can occur without any prior preeclamptic signs or symptoms.

Eclampsia typically begins with convulsions or fits, which can happen after 20 weeks of pregnancy or within 48 hours post-birth. These fits are characterized by involuntary, jerky movements of the arms, legs, neck, or jaw and usually last less than a minute. While most women recover fully, severe cases can lead to permanent disability or brain damage. Magnesium sulfate is commonly used to reduce the risk of eclampsia and maternal death.

Abruptio Placentae

In Abruptio Placentae condition, the placenta may tear away from the inner wall of the uterus before delivery. This can occur if the blood vessels leading to the placenta rupture due to high blood pressure and cause heavy bleeding.

Cardiovascular disease

Preeclampsia may increase your risk of developing cardiovascular disease (heart disease) in the future.

Stroke

High blood pressure can sometimes affect the blood flow to the brain, which may lead to a condition called a cerebral hemorrhage, or stroke. If this happens, the brain may receive less oxygen and nutrients, which can impact brain function. Prompt treatment can help minimize the effects and support recovery.

What are the treatment options for preeclampsia?

Severe preeclampsia can be fatal to the mother and baby. The most effective treatment for preeclampsia is to deliver the baby. After delivery, the mother's blood pressure usually returns to normal.

In general, if the mother is well nourished, follows the doctor's advice about bed rest, and if her blood pressure is controlled within normal range, the baby should not be affected.

At the hospital, the mother and baby would be monitored by regular blood pressure checks to monitor blood pressure levels. Urine samples would also be checked regularly to measure protein levels. Ultrasound scans would also be carried out to measure the baby's growth, the amount of amniotic fluid, and blood flow through the placenta. Cardiotocography is also done to monitor the baby's heart rate.

Medications are also recommended as they help lower blood pressure, thereby reducing the risk of stroke in the mother.

How is preeclampsia prevented?

Routine visits to the doctor, starting early in the pregnancy are vital. Regular checkups may be able to detect changes in blood pressure before it leads to complications in the pregnancy. Severe cases usually involve those without planned regular antenatal checkups who only visit their doctors late in the pregnancy.

Low-dose aspirin - When administered to women with moderate to high-risk preeclampsia, low-dose aspirin decreases the incidence of preeclampsia and related adverse pregnancy outcomes (preterm delivery, growth restriction) by 10 to 20 percent.

For women who have had preeclampsia before, it is crucial to be aware of the symptoms of preeclampsia and regularly monitor blood pressure during pregnancy. If you have other health issues, speak to your doctor in order for them to be well-managed to avoid potential complications.

What are the other high blood pressure disorders during pregnancy?

Besides preeclampsia, three other high blood pressure disorders can occur when you are pregnant:

Gestational hypertension - Typically begins after the 20th week. It does not cause high levels of protein in the urine or features of preeclampsia. Gestational hypertension usually resolves after delivery. However, it should be monitored as some women with this condition may develop preeclampsia.
Chronic hypertension - This high blood pressure disorder was already present before pregnancy or occurs before the 20th week.
Chronic hypertension with superimposed preeclampsia - In this condition, high blood pressure was present before pregnancy. However, the condition worsens with increasing amounts of protein in the urine, and the mother develops signs and symptoms of preeclampsia.

What is postpartum preeclampsia?

Postpartum preeclampsia is similar to preeclampsia but starts only after your baby is delivered. It usually begins within 48 hours of giving birth until 6 weeks after delivery. Symptoms of postpartum preeclampsia are similar to preeclampsia.

Expert Preeclampsia Care at Gleneagles Hospital Penang

At Gleneagles Hospital Penang, we prioritize the health of both mother and baby. Preeclampsia can be effectively managed with early diagnosis and expert care. Trust our experienced Obstetrics & Gynaecology (O&G) team to guide you through a safe pregnancy. Book a consultation today to ensure the best care for you and your baby.

References

National Health Services. Pre-eclampsia. Available at: https://www.nhs.uk/conditions/pre-eclampsia/ [Accessed on 12 September 2022]
August P and Sibai BM. Preeclampsia: Clinical Features and diagnosis. In: UpToDate, Post TW (Ed), UpToDate, Waltham, MA. [Accessed on 12 September 2022]
Norwits ER. Patient Education: Preeclampsia (Beyond the Basics). In: UpToDate, Post TW (Ed), UpToDate, Waltham, MA. [Accessed on 12 September 2022]
https://www.nhs.uk/conditions/pre-eclampsia/complications/