---
title: Hypertension in pregnancy and pre-eclampsia
description: The forms of high blood pressure in pregnancy, why pre-eclampsia, eclampsia and HELLP syndrome are dangerous, how they are found, which treatment approaches clinical guidelines describe, what matters after the birth, and when to call an ambulance.
type: disease
aliases:
  - high blood pressure in pregnancy
  - hypertensive disorders of pregnancy
  - gestational hypertension
  - pregnancy-induced hypertension
  - chronic hypertension in pregnancy
  - pre-eclampsia
  - preeclampsia
  - toxaemia of pregnancy
  - eclampsia
  - HELLP syndrome
  - HDP
sources:
  - tier: guideline
    org: minzdrav-rf
    title: Преэклампсия. Эклампсия. Отеки, протеинурия и гипертензивные расстройства во время беременности, в родах и послеродовом периоде
    year: 2024
    url: https://cr.minzdrav.gov.ru/view-cr/637_2
  - tier: guideline
    org: esc
    title: 2025 ESC Guidelines for the management of cardiovascular disease and pregnancy
    year: 2025
    doi: 10.1093/eurheartj/ehaf193
    url: https://doi.org/10.1093/eurheartj/ehaf193
  - tier: guideline
    org: nice
    title: 'Hypertension in pregnancy: diagnosis and management (NG133)'
    year: 2023
    url: https://www.nice.org.uk/guidance/ng133
  - tier: reference
    org: msd-manuals
    title: Preeclampsia and Eclampsia (MSD Manual Professional Version)
    year: 2025
    url: https://www.msdmanuals.com/professional/gynecology-and-obstetrics/abnormalities-of-pregnancy/preeclampsia-and-eclampsia
  - tier: reference
    org: msd-manuals
    title: Hypertension in Pregnancy (MSD Manual Professional Version)
    year: 2024
    url: https://www.msdmanuals.com/professional/gynecology-and-obstetrics/pregnancy-complicated-by-disease/hypertension-in-pregnancy
  - tier: guideline
    org: who
    title: Pre-eclampsia (WHO fact sheet)
    year: 2026
    url: https://www.who.int/news-room/fact-sheets/detail/pre-eclampsia
sources_checked: 2026-10-14
review: null
---

Hypertensive disorders of pregnancy is the general name for several conditions in which blood pressure is raised during pregnancy.<Cite n={[1, 2]} /> Blood pressure may already be raised before pregnancy or in its first half (chronic hypertension), or rise for the first time in the second half of pregnancy (gestational hypertension).<Cite n={[1, 2]} /> Pre-eclampsia holds a special place among them: raised blood pressure is joined by protein in the urine or by signs of damage to the mother's other organs or to the placenta.<Cite n={[1, 2, 3]} /> Pre-eclampsia can progress to eclampsia, an attack of seizures; both conditions can be life-threatening.<Cite n={6} />

Hypertensive disorders of pregnancy are one of the leading causes of death in mothers, both worldwide and in Russia, but with proper monitoring and treatment most severe outcomes can be avoided.<Cite n={[1, 6]} /> High blood pressure outside pregnancy is covered in the article on [hypertension](../hypertension/).

<Diagram name="hypertension-in-pregnancy">
  <p slot="normal">
    The diagram shows part of the wall of the uterus with the placenta lying on it. Spiral arteries in
    the uterine wall carry the mother's blood to the placenta.<Cite n={4} /> For comparison, in the
    normal state these arteries are drawn wide and the blood flow to the placenta is plentiful.
  </p>
  <p slot="disease">
    The cause of pre-eclampsia is not fully known; according to the current theory, the spiral
    arteries are not properly remodelled, and less blood reaches the placenta.<Cite n={[1, 4]} /> Then
    the inner lining of the mother's blood vessels is damaged, and the placenta releases substances
    into the blood that disturb how the vessels work.<Cite n={[1, 4]} /> The mother's blood vessels
    narrow, blood pressure rises, and her organs, above all the brain, kidneys and liver, get less
    blood and can be harmed.<Cite n={[1, 4]} /> The baby also gets less blood, so it may grow
    poorly.<Cite n={5} />
  </p>
</Diagram>

## Why it happens

<Patient>

The exact cause of pre-eclampsia is not known; the main theory links it to the placenta (see the diagram).<Cite n={[1, 4]} /> Chronic hypertension is raised blood pressure that a woman already had before pregnancy or that appeared in its first half.<Cite n={[1, 2]} /> It may be ordinary (primary) [hypertension](../hypertension/) or secondary hypertension, when another disease raises blood pressure.<Cite n={[2, 3]} /> Both chronic and gestational hypertension increase the risk of pre-eclampsia.<Cite n={5} />

The risk of pre-eclampsia is higher if raised blood pressure or pre-eclampsia occurred in a previous pregnancy, and with chronic hypertension, chronic kidney disease, diabetes and some autoimmune diseases (for example, systemic lupus erythematosus).<Cite n={[2, 3]} /> A first pregnancy, a multiple pregnancy, marked obesity, pre-eclampsia in close female relatives, older maternal age and a long gap since the previous pregnancy also matter.<Cite n={[2, 3, 6]} /> Having a risk factor does not mean pre-eclampsia will definitely develop, but doctors monitor such a pregnancy more closely.<Cite n={6} />

</Patient>

<Student>

ESC 2025 classification: pre-existing (chronic) hypertension, primary or secondary; gestational hypertension; pre-eclampsia; pre-existing hypertension with superimposed pre-eclampsia; antenatally unclassifiable hypertension (reassessed at or after 6 weeks post-partum).<Cite n={2} /> According to the Russian Ministry of Health guideline, chronic hypertension is BP ≥140/90 mmHg before pregnancy or in the first 20 weeks, usually persisting for more than 42 days after the birth; gestational hypertension is a rise in BP first recorded after week 20, without significant proteinuria.<Cite n={1} /> Gestational hypertension usually resolves within 6 weeks after the birth.<Cite n={2} /> The Russian Ministry of Health guideline states that gestational hypertension developing before 34 weeks is accompanied by pre-eclampsia in 25% of cases.<Cite n={1} />

The pathogenesis of pre-eclampsia is not fully understood. The Russian Ministry of Health guideline describes a two-stage theory: shallow trophoblast invasion leads to inadequate remodelling of the spiral arteries, followed by maternal endothelial dysfunction and an imbalance between angiogenic and antiangiogenic factors; symptoms resolve only with removal of the antiangiogenic factor sFlt-1 secreted by the placenta.<Cite n={1} /> According to MSD, vasospasm is promoted by decreased prostacyclin and increased endothelin and soluble Flt-1; the coagulation system is activated.<Cite n={4} /> The Russian Ministry of Health guideline distinguishes early-onset (before 34 weeks) and late-onset pre-eclampsia: early onset carries a higher risk for mother and child, and after 34 weeks the mother's cardiovascular system and haemodynamics take part in its development.<Cite n={1} />

High risk factors for pre-eclampsia in ESC 2025: hypertensive disorders in a previous pregnancy, chronic hypertension, chronic kidney disease, type 1 or type 2 diabetes, autoimmune diseases (SLE, antiphospholipid syndrome), assisted reproduction in the current pregnancy; moderate: nulliparity, age ≥40 years, a pregnancy interval of more than 10 years, BMI ≥35 kg/m² at the first visit, a family history of pre-eclampsia, multi-fetal pregnancy.<Cite n={2} /> NICE gives the same list, but without assisted reproduction.<Cite n={3} />

The sources give different frequencies. According to the Russian Ministry of Health guideline, hypertensive disorders occur in 5–10% of pregnancies and pre-eclampsia in 2–8%; according to WHO, pre-eclampsia affects 3–8% of women who give birth worldwide, and hypertensive disorders account for around 16% of maternal deaths.<Cite n={[1, 6]} />

</Student>

## Symptoms

<Patient>

Pre-eclampsia may cause no symptoms for a long time and, without treatment, suddenly progress to eclampsia.<Cite n={[4, 6]} /> That is why blood pressure is measured at every visit to the doctor, and the Russian guideline advises pregnant women to measure it regularly at home too.<Cite n={1} />

Seek medical help straight away if you have a severe headache, problems with vision (blurring, flashing or "spots" before the eyes), severe pain just below the ribs or in the upper abdomen, vomiting, or sudden swelling of the face, hands or feet.<Cite n={[3, 6]} /> When to call an ambulance is described in the section below. Swelling on its own is not required for a diagnosis of pre-eclampsia; swelling of the face and hands is more concerning, for example when a ring no longer fits on the finger.<Cite n={[1, 4]} /> Severe pre-eclampsia can cause breathlessness from fluid on the lungs and a fall in the amount of urine.<Cite n={4} />

Without treatment, pre-eclampsia can lead to eclampsia, HELLP syndrome (breakdown of red blood cells, liver damage and a low platelet count), damage to the kidneys, liver and brain, placental abruption, preterm birth, poor growth and death of the baby, and death of the mother.<Cite n={6} /> Pre-eclampsia and eclampsia can also occur after the birth: most often in the first days, but sometimes several weeks later.<Cite n={[1, 4]} />

</Patient>

<Student>

According to NICE and ESC, organ involvement in pre-eclampsia includes neurological complications (eclampsia, altered mental status, blindness, stroke, clonus, severe headaches, persistent visual scotomata), kidney and liver involvement (including right upper quadrant or epigastric pain), haematological complications (thrombocytopenia, DIC, haemolysis) and uteroplacental dysfunction: fetal growth restriction, abnormal umbilical artery Doppler waveforms or stillbirth.<Cite n={[2, 3]} /> According to the Russian Ministry of Health guideline, impending eclampsia is signalled by neurological symptoms, worsening headache, visual disturbances, epigastric and right upper quadrant pain, breathlessness, agitation or drowsiness; however, 25% of women have no warning symptoms.<Cite n={1} /> Eclampsia is seizures in pre-eclampsia of any severity in the absence of other causes.<Cite n={1} />

The Russian Ministry of Health guideline calls HELLP syndrome a potentially fatal manifestation of pre-eclampsia: thrombocytopenia is required for the diagnosis, whereas hypertension occurs in more than half of cases and is not required.<Cite n={1} /> According to MSD, some women with HELLP syndrome have neither hypertension nor proteinuria.<Cite n={4} /> Among maternal complications MSD lists pulmonary oedema, acute kidney injury, liver rupture, cerebral haemorrhage and placental abruption, and among fetal ones growth restriction, oligohydramnios and stillbirth.<Cite n={4} />

</Student>

## How it is diagnosed

<Patient>

If the doctor suspects pre-eclampsia, they test the urine for protein and order blood tests: platelet count and measures of liver and kidney function.<Cite n={[1, 4]} /> There may be no protein in the urine: pre-eclampsia is also diagnosed from signs of damage to other organs.<Cite n={[1, 4]} /> The baby's condition is checked with ultrasound (growth, placenta and amniotic fluid) and a recording of the baby's heartbeat, cardiotocography.<Cite n={[1, 4]} />

If very high blood pressure appears in a pregnant woman for the first time, the doctor may look for other causes, such as [renal artery stenosis](../renal-artery-stenosis/) or [coarctation of the aorta](../coarctation-of-the-aorta/).<Cite n={5} />

</Patient>

<Student>

Hypertension in pregnancy is systolic BP ≥140 and/or diastolic BP ≥90 mmHg; the Russian Ministry of Health guideline requires the mean of at least two measurements.<Cite n={[1, 3]} /> Pre-eclampsia is hypertension after week 20 combined with proteinuria or at least one sign of maternal organ dysfunction or uteroplacental dysfunction.<Cite n={[1, 2, 3]} /> Quantitative thresholds for proteinuria and laboratory values differ between guidelines, so they are not given here.

When pre-eclampsia is suspected, the Russian Ministry of Health guideline recommends urine protein and albumin/creatinine ratio, platelet count, blood biochemistry, and fetal ultrasound with fetometry and assessment of the placenta and amniotic fluid.<Cite n={1} /> The Russian Ministry of Health guideline calls the sFlt-1/PlGF ratio reliable but not yet widely available; NICE recommends PLGF-based testing to help rule out pre-eclampsia when it is suspected.<Cite n={[1, 3]} /> The risk of pre-eclampsia is calculated as early as the first trimester: from risk factors, mean arterial pressure, the uterine artery pulsatility index and PlGF.<Cite n={1} /> ESC suggests ambulatory or home BP monitoring to exclude white-coat and masked hypertension (IIa C).<Cite n={2} />

</Student>

## How it is treated

<Patient>

Treatment of pre-eclampsia depends on how severe it is and how far the pregnancy has progressed; its aim is to prevent complications in the mother and baby.<Cite n={6} /> Medicines are chosen and prescribed by a doctor. Do not start, stop or change medicines on your own.

If blood pressure was raised before pregnancy, it is better to plan the pregnancy with a doctor: some blood pressure medicines are dangerous for the baby during pregnancy, and the doctor replaces them with permitted ones in advance.<Cite n={[1, 3, 5]} /> Raised blood pressure in pregnancy is lowered with medicines that are acceptable in pregnancy.<Cite n={[2, 5]} /> The doctor takes into account that lowering blood pressure with medicines can reduce the blood flow to the placenta.<Cite n={5} /> Very high blood pressure in a pregnant woman is an emergency treated in hospital.<Cite n={2} />

Pre-eclampsia can be cured only by giving birth, although it sometimes appears after the birth.<Cite n={[1, 4]} /> Doctors decide when the baby should be born by weighing the danger of pre-eclampsia against the risk to the baby of being born too early.<Cite n={[1, 4]} /> In severe pre-eclampsia and eclampsia, the woman is urgently admitted to the intensive care unit of a maternity hospital, where her blood pressure is lowered and she is given a medicine to prevent and treat seizures.<Cite n={[1, 4]} /> If the baby is likely to be born early, the doctor may prescribe medicines that speed up maturation of the baby's lungs.<Cite n={[1, 6]} />

For women at high risk of pre-eclampsia, a doctor may prescribe preventive medicine; such medicines should not be taken without a prescription.<Cite n={[1, 2, 3]} /> Bed rest, salt restriction, vitamins C and E and diuretics are not recommended to prevent pre-eclampsia.<Cite n={[1, 3]} />

After the birth, blood pressure and wellbeing continue to be monitored: the danger of worsening persists in the first days.<Cite n={1} /> If blood pressure stays raised for more than a few weeks after the birth, it may be chronic hypertension, and treatment is chosen by a general practitioner.<Cite n={[2, 4]} /> Blood pressure treatment can be adapted to allow breastfeeding.<Cite n={3} />

Hypertension in pregnancy and pre-eclampsia are linked to a higher risk of hypertension and heart and blood vessel disease later in life.<Cite n={[1, 3]} /> So after the birth it is worth seeing a general practitioner, having your cardiovascular risk assessed, not smoking, and keeping a healthy weight and lifestyle.<Cite n={[1, 2, 3]} /> In a later pregnancy these disorders recur in about one woman in five.<Cite n={3} />

</Patient>

<Student>

ESC 2025: target BP in pregnancy below 140/90 mmHg (I B); in gestational hypertension, drug treatment is started at BP ≥140/90 mmHg (I B); systolic BP ≥160 or diastolic BP ≥110 mmHg in a pregnant woman is an emergency, and treatment in hospital is recommended (I C).<Cite n={2} /> For hypertension in pregnancy ESC recommends a centrally acting drug, certain beta-blockers and dihydropyridine calcium channel blockers; ACE inhibitors, ARBs and aldosterone antagonists are avoided in pregnancy because of harm to the fetus.<Cite n={[2, 5]} /> Specific drugs and doses are not given here.

The definitive treatment of pre-eclampsia is delivery; the risk of preterm delivery is balanced against gestational age, fetal growth restriction, fetal distress and the severity of pre-eclampsia.<Cite n={4} /> ESC recommends expediting delivery in pre-eclampsia with adverse markers such as haemostatic disorders (I C).<Cite n={2} /> In severe pre-eclampsia and eclampsia the Russian Ministry of Health guideline recommends emergency admission to the intensive care unit of a level 3 obstetric hospital; management rests on anticonvulsant therapy, BP control and delivery.<Cite n={[1, 4]} /> When preterm delivery is expected, prophylaxis of fetal respiratory distress syndrome with corticosteroids may be given.<Cite n={[1, 6]} /> ESC recommends drug prophylaxis of pre-eclampsia for women with one high or two moderate risk factors (I A).<Cite n={2} />

According to the Russian Ministry of Health guideline, the risk of worsening usually persists for 7 days after the birth.<Cite n={1} /> For hypertension persisting beyond 6 weeks to 3 months post-partum, ESC recommends antihypertensive therapy following current guidelines, with reference to lactation status (I B).<Cite n={2} /> ESC 2025 introduced a new section on the long-term effects of adverse pregnancy outcomes: cardiovascular risk assessment and counselling on a healthy lifestyle are recommended for all women with such outcomes (I B).<Cite n={2} /> NICE puts the overall risk of recurrence of a hypertensive disorder in a future pregnancy at about 1 in 5.<Cite n={3} />

</Student>

## When to call an ambulance

Call your local emergency number (112 in the EU, 911 in the US and Canada, 999 in the UK) if a pregnant woman or a woman who has recently given birth has seizures or loses consciousness, or has a severe headache, problems with vision, severe pain below the ribs on the right or in the upper abdomen, vomiting, sudden swelling of the face and hands, breathlessness or very high blood pressure on a home monitor.<Cite n={[1, 2, 3, 4]} /> Eclampsia can start without warning signs, and pre-eclampsia can develop after the birth, so these signs are dangerous in the first weeks after the birth too.<Cite n={[1, 4]} />

Very high blood pressure during pregnancy is an emergency; the general signs of a hypertensive crisis are described in the article on [hypertensive crisis](../hypertensive-crisis/).<Cite n={2} /> Breathlessness in pre-eclampsia can be caused by fluid on the lungs or by the strain on the heart of pumping against high blood pressure.<Cite n={4} /> A heart muscle disease that can also be linked to pregnancy is described in the article on [peripartum cardiomyopathy](../peripartum-cardiomyopathy/).

As with any heart or blood vessel condition, call an ambulance for fainting, chest pain or severe breathlessness: this is the site's general safety rule, repeated at the bottom of every page.

<Quiz />