Hypertension in pregnancy: symptoms and risks

Definition of hypertension in pregnancy – values

1. Arterial diastolic pressure (minimum) > 90 mmHg on two occasions 4 hours apart
2. Single measurement of diastolic pressure >110 mmHg

Classification

1. Light: 90-100 / 140-149 mmHg
2. Medium: 100-109 / 150-159 mmHg
3. Severe: >110 / 160 mmHg

Changes in circulation during pregnancy

1. Increased cardiac output
2. Increase in volume of intracellular and extracellular fluid
3. Arterial pressure drop, reaching the minimum about halfway through pregnancy
4. Decreased arterial resistance
5. Dilation of renal vessels
6. Stimulation of the renin-angiotensin-aldosterone system

Chronic high blood pressure undetected before pregnancy may be masked by an initial drop in pressure.

This can lead to an evaluation error, for example, the doctor might make the diagnosis of pregnancy hypertension, rather than that of chronic high pressure.

High blood pressure in pregnant women is a matter of serious concern.

Hypertension:

• Before the twentieth week, it is called chronic, usually the patient had elevated levels before she became pregnant.
• After the twentieth week, pregnancy hypertension

Women who had high blood pressure before their pregnancy are more likely to have high blood pressure during pregnancy.

Classification of high blood pressure in pregnancy High
blood pressure

chronic Hypertension diagnosed before pregnancy or before the 20th week of pregnancy

Gestational hypertension Hypertension that occurs after the 20th week of pregnancy, without protein in the urine

Preeclampsia Hypertension and marked proteinuria, may occur in patients with gestational or chronic hypertension

Severe preeclampsia Preeclampsia with high blood pressure and/or symptoms and/or blood changes Eclampsia Preeclampsia and convulsions

HELLP syndrome Hemolysis, increased transaminases, decreased platelets.

High gestational blood pressure

While chronic hypertension can be treated early because it occurs before pregnancy, gestational hypertension is difficult to prevent because it occurs suddenly.

Symptoms of gestational hypertension

In the second and third trimesters, but also only a few days after delivery, the following may occur:

• Sudden increase in body weight (more than 3 kg in 7 days),
• Sudden increase in arterial pressure,
• Massive swelling,
• decreased urine production,
• Headache
• Blurred vision.

Diagnostic examinations

The main investigations are:

• Holter blood pressure measurement to detect sudden pressure increases,
• Proteinuria measurement over 24 hours to see if the patient also suffers from preeclampsia,
• levels of urea and creatinine, which are elevated in case of preeclampsia,
• analysis of albumin in the blood – the value is decreased in case of endothelial damage,
• Complete blood count – haemolysis (destruction of red blood cells) reduces haemoglobin,
• Ultrasound (between the 26th and 28th week of pregnancy) to evaluate the growth of the fetus.
• Blood smear to check whether haemolysis or thrombocytopenia (reduction of platelets) is present.

One can distinguish the form:

1. Severe (hospitalisation required),
2. Moderate or mild (outpatient treatment).

Preeclampsia

Preeclampsia is a syndrome characterized by:

1. Hypertension
2. protein in the urine,
3. Edema (swelling), especially on the hands and face.

However, according to the guidelines of the American College of Obstetricians and Gynecologists, the presence of protein in the urine is not a necessary element for preeclampsia to develop.

In the absence of proteinuria, the disease is diagnosed in the case of:

• reduction of platelets in the blood,
• renal and hepatic problems,
• fluid in the lungs,
• Signs of brain disorders, such as seizures or blurred vision.

25% of women with chronic hypertension develop preeclampsia.

Mild preeclampsia

1. Arterial blood pressure between 90-109 / 150-159 mmHg
2. Proteinuria 0.3-5 g/24 hours
3. Lack of symptoms

Severe preeclampsia

• PA ≥ 160/110 mmHg
• Proteinuria ≥ 5 g/24 hours
• Decreased urine production, visual disturbances and neurological disorders
• Changes in liver enzymes and platelets
• Decreased growth of the fetus

Preeclampsia can begin around the 20th week and lead to disorders in some organs of the pregnant woman, including:

1. Nephritic
2. Brain
3. Placenta
4. Liver.

Risk factors of preeclampsia

1. Diabetes – 50%
2. Chronic hypertension – 20%
3. Twin birth – 20/30%
4. Birth rate – 6-10%
5. Age > 40 years
6. Interval between pregnancies greater than 10 years
7. If other family members have suffered from preeclampsia
8. Preeclampsia in a previous pregnancy
9. BMI (Body Mass Index) > 30 kg/m²
10. Presence of heart disease
11. Kidney disease

Risks of hypertension in pregnancy

Preeclampsia increases the risk of placental detachment from the inner uterine wall before birth.

Significant detachment can lead to severe bleeding that endangers the lives of mother and child.

Organ damage

Hypertension can cause damage to:

• Brain
• Heart
• Lungs
• Nephritic
• Liver
• Other important organs.

In the most severe cases, it can be life-threatening.

Risks of hypertension for the fetus

Preeclampsia can decrease blood flow to the placenta. If the placenta does not receive enough blood, the child receives too little oxygen and nutrients.

The consequences can be:

• Low birth weight,
• Premature birth.

Premature birth (between 22 and 37 weeks) can cause:

1. Respiratory problems
2. Increase in risks of infection and other complications for the child.

Most women can give birth to a healthy child if preeclampsia is detected and treated early.

Consequences of hypertension in pregnancy

Detachment of a normally embedded placenta

In case of partial or complete detachment of the placenta with and without significant blood loss from the genital area or acute childhood disorders, there is an immediate indication for induction of labor.

There is an indication for a caesarean section if the placenta detaches from the basal plate after the twentieth week.

HELLP syndrome

HELLP syndrome (H for hemolysis, EL for increasing liver enzymes, LP for thrombocytopenia) is a disease that occurs only in 0.2-0.6% of cases in pregnancy.

Women at risk are:

• At an advanced age,
• Light-skinned
• Have already given birth once.

Usually this occurs in the third trimester of pregnancy.

Pathophysiology – severe microangiopathic hemolytic anemia can affect some organs: liver, kidney, up to multiple organ failure.

The following may occur:

• thrombi caused by platelets in the peripheral vessels,
• Microangiopathic hemolysis – red blood cells are destroyed in the small blood vessels.
• Ischemia in the organs.

Diagnostic criteria

Hemolysis:

1. Abnormalities of the peripheral smear
2. Total bilirubin > 1.2 mg/dl
3. Lactate dehydrogenase (LDH) > 600 U/L
4. AST (Transaminase) > 70 U/L
5. Platelets < 100,000/mm³

Symptoms

• In 90% of cases, the patient has severe abdominal pain,
• In 50% of cases there is nausea and vomiting,
• The pain can radiate to the right shoulder and back,
• Ascites
• pleural effusion,
• Shortness of breath.

HELLP syndrome is associated with a 1% maternal risk of death.

Complications may include:

• Pulmonary oedema (8% of cases)
• Acute renal impairment (3%)
• Disseminated intravascular coagulation disorder (CID) (15%)
• Placental detachment (9%)
• Hepatic insufficiency and bleeding (1%)
• Acute respiratory distress syndrome in adults (< 1%)
• Sepsis (< 1%)
• Stroke (< 1%)

Therapy:

• fresh plasma transfusion,
• cortisone (dexametasone) in the dosage of 20 mg per day,
• Induction of childbirth.

Eclampsia

The term “eclampsia” refers to the appearance of convulsions (or coma) in a pregnant woman who has the symptoms of preeclampsia.

In the Western world, it occurs with a frequency of about 1 in 2000 births.

It can occur:

• Before birth (40% of cases),
• During labor (18%),
• In the first 20 days after birth (44%).

90% of cases occur in pregnancy after the 28th week, 1% of cases before the 20th week.

Therapy:

1. benzodiazepine + magnesium sulfate (4 g intravenously in the first 15 minutes, and then 1-3 grams every hour),
2. mannitol 5 %,
3. Induction of labour.

Delayed/terminated fetal growth (IUGR)

The parameters to consider are:

• Estimated weight < based on the 10th percentile of week of pregnancy and gender, or,
• Permanent reduction of abdominal circumference and maintenance of head circumference associated with changes in arterial umbilical perfusion.

Diagnosis

• Doppler sonography of the umbilical artery,
• Fetal biometrics (ultrasound measurements) every 2nd week.

If the diagnosis confirms delayed infant growth, birth must be initiated.

What to do? Therapy for high blood pressure in pregnancy

Medications for chronic hypertension

• Preferred choice: alpha-methyldopa (Aldomet ®), dose 250-2000 mg/day
• Second choice: Labetalol (Trandate ®), dose 200-1200 mg/day. Some data indicate that the use of labetalol can harm child growth (Von Dadelszen 2000, Easterling 1999)
• With concomitant preeclampsia: nifedipine (Adalat ® – contraindicated before the twentieth week of pregnancy)

Medication for preeclampsia

• Preferred choice: nifedipine (10-40 mg/day) or labetalol (200-1200 mg/day)
• Second choice: in addition to labetalol, transdermal nitroglycerin (5-10 mg/day)
• Third choice: clonidine (catapresan ®)

Conservative treatment is not recommended by all scientific associations, in the United States of America it is the early induction of childbirth.

According to a study by K. M. Petersen et all – (Department of Cardiology, Rigshospitalet, University Hospital Copenhagen, Copenhagen, Denmark), beta-blockers during pregnancy can cause:

• Delayed growth,
• Premature birth
• Perinatal mortality.

Bed rest in left-sided position

According to some authors, bed rest increases blood flow to the kidneys and systemic circulation.

The result is a reduction in high blood pressure.

However, the research shows:

• That this does not stop the progression to severe forms of hypertension in pregnancy,
• That the risk of thrombosis and embolism increases.

Induction of childbirth.

Childhood indication for induction of labour

1. Ultrasound:
2. Oligohydramnios (reduction of amniotic fluid) (AFI < 3)
3. Reversal of diastolic flow in the umbilical artery
4. Severe underdevelopment of the fetus (< 5th percentile)

Maternal indication for induction of labour

• Blood pressure values that are resistant to treatment (no lowering, although the patient takes tablets)
• presence of clinical symptoms of impending eclampsia: headache, scotomas (spots or fibrillation in the visual field area), loss of vision in one eye, tinnitus, dizziness, pain in the upper abdomen, nausea and vomiting, peripheral neurological deficits, change in consciousness status;
• HELLP syndrome
• Heart failure, acute pulmonary edema, acute cerebral events
• Hepatomegaly
• Oligoanuria (decreased urine output) < 0.5 ml/kg/hour despite fluid infusion
• Birth complications (premature rupture of the amniotic sac, appearance of uterine contractions, premature detachment of the placenta, bleeding)

Therapy may depend on the week of pregnancy:

• Before the 24th week, the doctor usually advises an abortion;
• Between the 24th and 34th week, cortisone treatment is possible to maintain the pregnancy longer;
• After the 34th week and in the ninth month (35th, 36th, 37th, 38th, 39th and 40th week), the doctor advises induction of labor.

Diet and nutrition for hypertension in pregnancy

Along with physical activity, diet is the main natural treatment for hypertension.

Some foods can raise blood pressure, while others help lower levels.

What foods should you avoid?

Processed and preserved products contain salt and can cause hypertension.

According to the blood group diet, the following also applies:

1. High systolic blood pressure is caused by milk, dairy products and pork,
2. Minimal high pressure is caused by cereal products (pasta, rice, pizza, bread, corn, etc.).

What should you eat?

Plant foods (fruits and vegetables) have a low salt content and a significant potassium content. This leads to a reduction in blood pressure.

According to hygienism, a vegan diet with a large proportion of raw food is sufficient to reduce blood pressure to normal levels.

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