What is preeclampsia caused by

Pre-eclampsia - Causes - NHS

Pre-eclampsia is thought to be caused by the placenta not developing properly due to a problem with the blood vessels supplying it. The exact cause isn't fully understood.

Placenta

The placenta is the organ that links the mother's blood supply to her unborn baby's blood supply.

Food and oxygen pass through the placenta from mother to baby. Waste products can pass from the baby back into the mother.

To support the growing baby, the placenta needs a large and constant supply of blood from the mother.

In pre-eclampsia, the placenta doesn't get enough blood. This could be because the placenta didn't develop properly as it was forming during the first half of the pregnancy.

The problem with the placenta means the blood supply between mother and baby is disrupted.

Signals or substances from the damaged placenta affect the mother's blood vessels, causing high blood pressure (hypertension).

At the same time, problems in the kidneys may cause important proteins that should remain in the mother's blood to leak into her urine, resulting in protein in the urine (proteinuria).

What causes problems with the placenta?

In the initial stages of pregnancy, the fertilised egg implants itself into the wall of the womb (uterus). The womb is the organ a baby grows inside during pregnancy.

The fertilised egg produces root-like growths called villi, which help to anchor it to the lining of the womb.

The villi are fed nutrients through blood vessels in the womb and eventually grow into the placenta.

During the early stages of pregnancy, these blood vessels change shape and become wider.

If the blood vessels don't fully transform, it's likely that the placenta won't develop properly because it won't get enough nutrients. This may lead to pre-eclampsia.

It's still unclear why the blood vessels don't transform as they should.

It's likely that inherited changes in your genes have some sort of role, as the condition often runs in families. But this only explains some cases.

Who's most at risk?

Some factors have been identified that could increase your chances of developing pre-eclampsia.

These include:

having an existing medical problem – such as diabetes, kidney disease, high blood pressure, lupus or antiphospholipid syndrome
previously having pre-eclampsia

Some factors also increase your chances by a small amount.

If you have 2 or more of these together, your chances are higher:

it's your first pregnancy – pre-eclampsia is more likely to happen during the first pregnancy than during any subsequent pregnancies
it's been at least 10 years since your last pregnancy
you have a family history of the condition – for example, your mother or sister has had pre-eclampsia
you're over the age of 40
you were obese at the start of your pregnancy – meaning you had a body mass index (BMI) of 35 or more
you're expecting twins or more, such as twins or triplets

If you're considered to be at a high risk of developing pre-eclampsia, you may be advised to take a 75 to 150mg dose of aspirin every day from when you're 12 weeks pregnant until your baby is born.

Evidence suggests this can lower your chances of developing the condition.

Page last reviewed: 28 September 2021
Next review due: 28 September 2024

Preeclampsia - Symptoms and causes

Overview

Preeclampsia is a complication of pregnancy. With preeclampsia, you might have high blood pressure, high levels of protein in urine that indicate kidney damage (proteinuria), or other signs of organ damage. Preeclampsia usually begins after 20 weeks of pregnancy in women whose blood pressure had previously been in the standard range.

Left untreated, preeclampsia can lead to serious — even fatal — complications for both the mother and baby.

Early delivery of the baby is often recommended. The timing of delivery depends on how severe the preeclampsia is and how many weeks pregnant you are. Before delivery, preeclampsia treatment includes careful monitoring and medications to lower blood pressure and manage complications.

Preeclampsia may develop after delivery of a baby, a condition known as postpartum preeclampsia.

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Symptoms

The defining feature of preeclampsia is high blood pressure, proteinuria, or other signs of damage to the kidneys or other organs. You may have no noticeable symptoms. The first signs of preeclampsia are often detected during routine prenatal visits with a health care provider.

Along with high blood pressure, preeclampsia signs and symptoms may include:

Excess protein in urine (proteinuria) or other signs of kidney problems
Decreased levels of platelets in blood (thrombocytopenia)
Increased liver enzymes that indicate liver problems
Severe headaches
Changes in vision, including temporary loss of vision, blurred vision or light sensitivity
Shortness of breath, caused by fluid in the lungs
Pain in the upper belly, usually under the ribs on the right side
Nausea or vomiting

Weight gain and swelling (edema) are typical during healthy pregnancies. However, sudden weight gain or a sudden appearance of edema — particularly in your face and hands — may be a sign of preeclampsia.

When to see a doctor

Make sure you attend your prenatal visits so that your health care provider can monitor your blood pressure. Contact your provider immediately or go to an emergency room if you have severe headaches, blurred vision or other visual disturbances, severe belly pain, or severe shortness of breath.

Because headaches, nausea, and aches and pains are common pregnancy complaints, it's difficult to know when new symptoms are simply part of being pregnant and when they may indicate a serious problem — especially if it's your first pregnancy. If you're concerned about your symptoms, contact your doctor.

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Causes

The exact cause of preeclampsia likely involves several factors. Experts believe it begins in the placenta — the organ that nourishes the fetus throughout pregnancy. Early in a pregnancy, new blood vessels develop and evolve to supply oxygen and nutrients to the placenta.

In women with preeclampsia, these blood vessels don't seem to develop or work properly. Problems with how well blood circulates in the placenta may lead to the irregular regulation of blood pressure in the mother.

Other high blood pressure disorders during pregnancy

Preeclampsia is one high blood pressure (hypertension) disorder that can occur during pregnancy. Other disorders can happen, too:

Gestational hypertension is high blood pressure that begins after 20 weeks without problems in the kidneys or other organs. Some women with gestational hypertension may develop preeclampsia.
Chronic hypertension is high blood pressure that was present before pregnancy or that occurs before 20 weeks of pregnancy. High blood pressure that continues more than three months after a pregnancy also is called chronic hypertension.
Chronic hypertension with superimposed preeclampsia occurs in women diagnosed with chronic high blood pressure before pregnancy, who then develop worsening high blood pressure and protein in the urine or other health complications during pregnancy.

Risk factors

Conditions that are linked to a higher risk of preeclampsia include:

Preeclampsia in a previous pregnancy
Being pregnant with more than one baby
Chronic high blood pressure (hypertension)
Type 1 or type 2 diabetes before pregnancy
Kidney disease
Autoimmune disorders
Use of in vitro fertilization

Conditions that are associated with a moderate risk of developing preeclampsia include:

First pregnancy with current partner
Obesity
Family history of preeclampsia
Maternal age of 35 or older
Complications in a previous pregnancy
More than 10 years since previous pregnancy

Other risk factors

Several studies have shown a greater risk of preeclampsia among Black women compared with other women. There's also some evidence of an increased risk among indigenous women in North America.

A growing body of evidence suggests that these differences in risk may not necessarily be based on biology. A greater risk may be related to inequities in access to prenatal care and health care in general, as well as social inequities and chronic stressors that affect health and well-being.

Lower income also is associated with a greater risk of preeclampsia likely because of access to health care and social factors affecting health.

For the purposes of making decisions about prevention strategies, a Black woman or a woman with a low income has a moderately increased risk of developing preeclampsia.

Complications

Complications of preeclampsia may include:

Fetal growth restriction. Preeclampsia affects the arteries carrying blood to the placenta. If the placenta doesn't get enough blood, the baby may receive inadequate blood and oxygen and fewer nutrients. This can lead to slow growth known as fetal growth restriction.
Preterm birth. Preeclampsia may lead to an unplanned preterm birth — delivery before 37 weeks. Also, planned preterm birth is a primary treatment for preeclampsia. A baby born prematurely has increased risk of breathing and feeding difficulties, vision or hearing problems, developmental delays, and cerebral palsy. Treatments before preterm delivery may decrease some risks.
Placental abruption. Preeclampsia increases your risk of placental abruption. With this condition, the placenta separates from the inner wall of the uterus before delivery. Severe abruption can cause heavy bleeding, which can be life-threatening for both the mother and baby.
HELLP syndrome. HELLP stands for hemolysis (the destruction of red blood cells), elevated liver enzymes and low platelet count. This severe form of preeclampsia affects several organ systems. HELLP syndrome is life-threatening to the mother and baby, and it may cause lifelong health problems for the mother.

Signs and symptoms include nausea and vomiting, headache, upper right belly pain, and a general feeling of illness or being unwell. Sometimes, it develops suddenly, even before high blood pressure is detected. It also may develop without any symptoms.
Eclampsia. Eclampsia is the onset of seizures or coma with signs or symptoms of preeclampsia. It is very difficult to predict whether a patient with preeclampsia will develop eclampsia. Eclampsia can happen without any previously observed signs or symptoms of preeclampsia.

Signs and symptoms that may appear before seizures include severe headaches, vision problems, mental confusion or altered behaviors. But, there are often no symptoms or warning signs. Eclampsia may occur before, during or after delivery.
Other organ damage. Preeclampsia may result in damage to the kidneys, liver, lung, heart, or eyes, and may cause a stroke or other brain injury. The amount of injury to other organs depends on how severe the preeclampsia is.
Cardiovascular disease. Having preeclampsia may increase your risk of future heart and blood vessel (cardiovascular) disease. The risk is even greater if you've had preeclampsia more than once or you've had a preterm delivery.

Prevention

Medication

The best clinical evidence for prevention of preeclampsia is the use of low-dose aspirin. Your primary care provider may recommend taking an 81-milligram aspirin tablet daily after 12 weeks of pregnancy if you have one high-risk factor for preeclampsia or more than one moderate-risk factor.

It's important that you talk with your provider before taking any medications, vitamins or supplements to make sure it's safe for you.

Lifestyle and healthy choices

Before you become pregnant, especially if you've had preeclampsia before, it's a good idea to be as healthy as you can be. Talk to your provider about managing any conditions that increase the risk of preeclampsia.

By Mayo Clinic Staff

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Preeclampsia and pregnancy | Ida-Tallinna Keskaigla

Preeclampsia and pregnancy

The purpose of this information leaflet is to provide the patient with information about the nature, occurrence, risk factors, symptoms and treatment of preeclampsia.

What is preeclampsia?

Pre-eclampsia is a disease that occurs during pregnancy and is characterized by high blood pressure and protein in the urine. Preeclampsia is one of the most common complications of pregnancy. Epilepsy-like seizures occur in severe preeclampsia and are life-threatening.

What symptoms may indicate the development of preeclampsia?

High blood pressure - blood pressure values are 140/90 mmHg. Art. or higher. If systolic (upper) or diastolic (lower) blood pressure rises by 30 mm Hg. Art. or more, then such an increase cannot be ignored.

Protein in urine - 300 mg in urine collected over 24 hours, or +1 value on a rapid test.

Swelling of the arms, legs or face , especially under the eyes or if the skin is pitted when pressed. Edema can occur in all pregnant women and is generally harmless, but rapidly developing edema should be taken into account.

Headache that does not improve after taking pain medication.

Visual disturbances - double vision or blurred vision, dots or flashes before the eyes, auras.

Nausea or pain in the upper abdomen - These symptoms are often mistaken for indigestion or gallbladder pain. Nausea in the second half of pregnancy is not normal.

Sudden weight gain - 2 kg or more per week.

As a rule, there is a mild course of the disease that occurs at the end of pregnancy and has a good prognosis. Sometimes, preeclampsia can worsen quickly and be dangerous to both mother and fetus. In such cases, rapid diagnosis and careful monitoring of the mother and child are of paramount importance.

Unfortunately, most women develop symptoms in the final stages of the disease. If you experience any of the above symptoms, you should contact your midwife, gynecologist, or the Women's Clinic emergency department.

Is preeclampsia called toxemia of pregnancy?

Previously, pre-eclampsia was really called toxicosis, or toxemia, since it was believed that the cause of the disease was toxins, that is, poisons in the blood of a pregnant woman.

What is the difference between preeclampsia and gestational hypertension?

Pregnancy hypertension is an increase in blood pressure above normal after the 20th week of pregnancy. With hypertension of pregnant women, protein in the urine is not observed.

What is HELLP syndrome?

HELLP syndrome is one of the most severe forms of preeclampsia. HELLP syndrome is rare and sometimes develops before symptoms of preeclampsia appear. Sometimes the syndrome is difficult to diagnose, as the symptoms resemble gallbladder colic or a cold.

When does preeclampsia occur?

Preeclampsia usually occurs after the 20th week of pregnancy. As a rule, preeclampsia goes away after delivery, but complications can occur up to six weeks after delivery, during which careful monitoring of the condition is necessary. If by the sixth week after birth, blood pressure does not return to normal, then you need to contact a cardiologist, who will begin treatment against hypertension.

What is the cause of preeclampsia?

The causes of the disease are still not clear, there are only unproven hypotheses.

How does the disease affect pregnant women and pregnancy?

Most preeclamptic pregnancies have a favorable outcome and a healthy baby is born. However, the disease is very serious and is one of the most common causes of death of the child and mother. Preeclampsia affects a woman's kidneys, liver, and other vital organs, and if left untreated, it can cause seizures (eclampsia), cerebral hemorrhage, multiple organ failure, and death.

How does the disease affect the fetus?

In preeclampsia, the fetus does not receive enough oxygen and nutrients to grow, and intrauterine growth retardation may occur. In addition, the placenta may separate from the uterine wall before the baby is born. Since the only treatment for preeclampsia is childbirth, sometimes a pregnancy has to be terminated prematurely. Until the 34th week of pregnancy, the lungs of the fetus have not yet matured, and steroid hormones are injected intramuscularly into the pregnant woman to prepare his lungs. In addition to the immaturity of the lungs, the health of a premature baby is threatened by many other diseases.

Who is at risk of developing preeclampsia?

Preeclampsia occurs in approximately 8% of pregnant women, many of whom have no known risk factors.

What are the risk factors for preeclampsia?

Patient-related risk factors

First pregnancy
Pre-eclampsia during a previous pregnancy
Age over 40 or under 18
High blood pressure before pregnancy
Diabetes before or during pregnancy
Multiple pregnancy
Overweight (BMI> 30)
Systemic lupus erythematosus or other autoimmune disease
Polycystic ovary syndrome
Long interval between two pregnancies

Risk factors associated with the patient's family

Pre-eclampsia in the mother's or father's family
Parental high blood pressure or heart disease
Diabetes mellitus

What is the prevention and treatment of preeclampsia

The first trimester screening or Oscar test also calculates the risk of preeclampsia in addition to the most common chromosomal disorders. In case of high risk, pregnant women are advised to take aspirin (acetylsalicylic acid) at a dose of 150 mg in the evenings until the 36th week of pregnancy. This helps reduce the chance of preeclampsia by the 34th week of pregnancy by up to 80%.

Childbirth is the only treatment for preeclampsia. Sometimes a child can be born naturally, but sometimes, if the disease is very acute, an emergency caesarean section is necessary. The best time to have a baby is after the 37th week of pregnancy. Bed rest, medications, and, if necessary, hospitalization can sometimes help bring the condition under control and prolong the pregnancy. Often, a doctor will refer a woman with preeclampsia to the hospital for observation, as the condition of the fetus and pregnant woman may suddenly worsen.

Does bed rest help?

Sometimes bed rest is enough to control mild preeclampsia. In this case, the patient often visits a doctor who measures blood pressure, does blood and urine tests, and monitors the course of the disease. The condition of the fetus is also often examined using a cardiotocogram (CTG) and ultrasound.

Are drugs used to treat preeclampsia?

High blood pressure sometimes requires medication. The medications used have few side effects, the drugs prescribed do not have much effect on the fetus, but are very important in the treatment of maternal high blood pressure.

Seizures are a rare but very serious complication of preeclampsia. Magnesium sulfate is sometimes given intravenously to prevent seizures in a pregnant woman with preeclampsia both during and after childbirth. It is safe for the fetus, but the mother may experience side effects such as hot flashes, sweating, thirst, visual disturbances, mild confusion, muscle weakness, and shortness of breath. All these side effects disappear when the drug is discontinued.

Can preeclampsia recur?

Preeclampsia does not necessarily recur in the next pregnancy, but the main risk factor for preeclampsia is the presence of preeclampsia in a previous pregnancy(s). Risk factors for relapse include the severity of the previous case and the woman's overall health during pregnancy. A woman who has previously had preeclampsia should consult a gynecologist during a new pregnancy or when planning a pregnancy.

ITK1013

The information material was approved by the Health Care Quality Committee of East-Tallinn Central Hospital on 11/30/2022 (Minutes No. 18-22).

Postpartum management of preeclampsia

HEALTH OF WOMAN. 2019.9(145): 8–13; doi 10.15574/HW.2019.145.8

I.V. Lakhno
Kharkiv Medical Academy of Postgraduate Education

Preeclampsia occurs only in humans during the second half of pregnancy and in the postpartum period, is characterized by the development of multiple organ arterial hypertension and leads to multiple organ failure syndrome. It is known that almost a third of cases of eclampsia occurs in the postoperative period. Patients with preeclampsia require careful monitoring of blood pressure and the appointment of antihypertensive drugs after delivery.

The pathogenesis and tactics of managing women in labor with preeclampsia that arose in de novo puerperia are not well understood. The greatest risk of stroke after childbirth remains within 10 days. During the manifestation of preeclampsia after childbirth, it is very important to start the use of antihypertensive drugs. First-line drugs should be used within 30 to 60 minutes of the diagnosis of severe preeclampsia to prevent cerebral hemorrhage. Labetalol or hydralazine are used to quickly lower blood pressure. Sublingual nifedipine can also be considered first-line therapy. The use of magnesium sulfate is necessary for the prevention of seizures in patients with severe preeclampsia. Against the background of an attack of eclampsia, a solution of magnesium sulfate is started to be administered intravenously at a dose of 4-5 g for 15-20 minutes, and then the infusion administration is continued at a dose of 1 g per hour during the day.

Uterine curettage is also a possible treatment for lowering blood pressure in women with preeclampsia. To date, there is not enough data on the safety of its use in terms of the risks associated with anesthesia, possible perforation of the uterus and the spread of infection against the background of endometritis. But curettage should be performed during caesarean section for women with preeclampsia.

The article presents its own observation of the systemic inflammatory response syndrome, which arose in a woman with initial mild preeclampsia after childbirth. Postpartum endomyometritis, which was caused by group B streptococcus, was supposed to play a triggering role in the progression of preeclampsia. The problem of polychemoresistance has led to the inability of traditional antimicrobial agents to prevent dissemination of infection after curettage. The systemic inflammatory response syndrome caused an increase in the severity of preeclampsia and the development of multiple organ failure.

Keywords: preeclampsia, postpartum period, antihypertensive drugs.

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