Diagnosing, assessing and managing pre-eclampsia

Module overview

Pre-eclampsia is a complex and unpredictable disorder that may occur during pregnancy. Its presentation ranges from mild to severe, and the condition may lead to the death of the mother and/or the baby in extreme cases. The earlier the disorder is detected and managed, the better the outcome. This module provides an outline of the disorder and its management, within the framework of UK and international guidelines. A series of suggested activities encourages the reader to reflect on the information provided within the context of their practice.

Keywords

antenatal, maternity, midwifery, midwives, pre-eclampsia, pregnancy

Aims

The aim of this module is to provide an overview of the origins and presentation of pre-eclampsia, screening for the disorder and appropriate management and to enhance the knowledge of nurses and support staff who may find themselves forming part of the larger multidisciplinary team, caring for pregnant women. This module explores assessment and management of pre-eclampsia, but it is not intended to be prescriptive.

Intended learning outcomes

After reading this module and completing the time out activities you should be able to:

• Describe the assessments that should be undertaken when a pregnant woman presents with healthcare concerns.
• Recognise and list the signs and symptoms of pre-eclampsia.
• Explain the possible causes of pre-eclampsia.
• Explain why early detection of the condition is important.
• Describe investigations undertaken to confirm a diagnosis of pre-eclampsia.
• Instigate timely and appropriate monitoring, referral and management of a woman with pre-eclampsia.

Introduction

Pre-eclampsia is described as ‘new hypertension presenting after 20 weeks [gestation] with significant proteinuria’ (National Institute for Health and Care Excellence (NICE) 2010). This simple definition gives little indication of the contradictory nature of pre-eclampsia and its associated complications.

Consider the following scenarios:

A woman, 39 weeks pregnant with her first baby, has developed increasingly severe abdominal pain throughout the day. She assumed initially that it was the start of labour but the pain, which is worse under her rib cage, is constant and unrelenting. The woman is normotensive and has a proteinuria result of 1+. She is seen by a doctor and is given codeine and paracetamol while waiting for her blood results. She soon feels much better.

A woman, 34 weeks pregnant with her third baby, seeks advice after passing a small amount of fresh blood while going to the toilet. Her uterus is slightly tender when palpated but otherwise she feels well. Her blood pressure is 160/105mmHg and she has a proteinuria result of 2+.
• A first-time mother is discharged home several hours after giving birth. Both her pregnancy and birth were uneventful. Nothing out of the ordinary was noted during her first postnatal visit with the midwife on day two. A follow-up appointment was made for day five at the postnatal clinic. On day four she developed a headache, which she attributed to fatigue. The headache persisted into the following day and the woman described feeling ‘out of sorts’. On arrival at the postnatal clinic, she was seen initially by the maternity care assistant who discovered that the woman’s blood pressure was 175/115mmHg and that she had a proteinuria result of 3+.

These scenarios appear to have little in common apart from the fact that the women are, or have just been, pregnant. Yet they were all diagnosed subsequently with pre-eclampsia. The blood results of the first woman showed that she had HELLP syndrome (haemolysis, elevated liver enzymes and low-platelet count), a severe and life-threatening presentation of the disorder. The first two scenarios took place in a maternity assessment unit, but the women could have attended the emergency department.

Awareness of pre-eclampsia symptoms

It is essential that those caring for pregnant women or for women in the early-postnatal period are aware of the warning signs of pre-eclampsia and are able to respond appropriately, within their professional scope. In the UK, the responsibility of screening for pre-eclampsia rests primarily with midwives and guidance has been produced to inform their practice (Action on Pre-eclampsia 2004, 2009).

Examples of situations where nursing input may be crucial include:

• A triage nurse in the emergency department assessing a pregnant woman with epigastric pain.
• An intensive care unit (ICU) nurse caring for a woman following an eclamptic fit.
• A neonatal ICU nurse caring for a baby whose mother is experiencing severe headache.

In accordance with The Code: Professional Standards of Practice and Behaviour for Nurses and Midwives (Nursing and Midwifery Council (NMC) 2015), nurses, and midwives, are required to ‘recognise and work within the limits of [their] competence’ and to make ‘timely and appropriate’ referrals. To this end, pregnant or postnatal woman seeking advice should also be given a maternity check by a midwife, GP or obstetrician regardless of their presenting concerns. Pre-eclampsia may also progress to a critical level between routine antenatal appointments. Therefore, it is important that healthcare professionals educate pregnant women on the signs and symptoms of the disorder, and provide clear guidance on who to contact should they have any healthcare concerns.

Learning Points

1. Pre-eclampsia is described as ‘new hypertension presenting after 20 weeks [gestation] with significant proteinuria'.
2. Nurses working emergency departments and intensive care units (ICUs) should be aware of pre-eclampsia symptoms.
3. It is important that healthcare professionals educate pregnant women on the signs and symptoms of the disorder, and provide clear guidance on who to contact should they have any healthcare concerns.

Causes of pre-eclampsia

The exact causes of pre-eclampsia are unknown, although its origins have been traced to the placenta. In a normal pregnancy, the developing placenta undergoes specific physiological changes to assist blood flow to the baby. In a woman with pre-eclampsia, normal physiological changes can be altered and placental perfusion decreased. The reasons for this are not understood fully, although a correlation between several factors has been made (Figure 1). These can be grouped into three classifications (Magee et al 2014):

Figure 1. Origins and effects of pre-eclampsia

• Immunological factors, for example first baby or new partner.
• Genetic factors, such as family history.
• Lowered threshold, for example pre-existing hypertension or chronic renal problems.

Alternatively, the placenta may experience increased demand, with multiple pregnancy for instance. Regardless of whether pre-eclampsia arises from an abnormally developed placenta or an increased placental load, a cascade of events is triggered, beginning with an inflammatory response in the endothelial lining of maternal blood vessels. This results in widespread vasoconstriction, increased vascular permeability and possible clotting dysfunction (Impey and Child 2012). Damage to maternal organs can follow, leading to a variety of potential complications. Reduced placental blood flow can mean that the fetus receives a lack of vital nutrients and oxygen (Lowe et al 2014).

The mechanisms underlying the development of pre-eclampsia can evolve early in pregnancy, but it rarely presents until after 20 weeks gestation. In some instances it becomes apparent only following delivery of the baby. Pre-eclampsia as a result of abnormal placental development is associated with earlier onset and more severe presentation of the disease than that caused by a larger placental site (Magee et al 2014).

Learning Points

1. In a woman with pre-eclampsia, normal physiological changes can be altered and placental perfusion decreased. The reasons for this could be immunological factors (first baby or new partner), genetic factors (family history) and lowered threshold (pre-existing hypertension or chronic renal problems).
2. Reduced placental blood flow can mean that the fetus receives a lack of vital nutrients and oxygen.
3. The mechanisms underlying the development of pre-eclampsia can evolve early in pregnancy, but it rarely presents until after 20 weeks gestation.

Clinical presentation

As pre-eclampsia progresses it can give rise to:

• Hypertension.
• Proteinuria.
• Oedema.
• Epigastric pain.
• Severe headache.
• Visual disturbances.

Screening for pre-eclampsia should always be undertaken in the presence of these symptoms, although they may have other causes. It is important to remember that the rate of progression of the condition varies. In some women, the onset is gradual, while in others the situation may become life threatening within hours.

Hypertension

Hypertension is one of the most common features of pre-eclampsia and serves often as the earliest warning of the disease. It may be defined as:

• Mild (140-149/90-99mmHg).
• Moderate (150-159/100-109mmHg).
• Severe (>160/110mmHg).

Severe hypertension demands urgent medical review and treatment, since it can cause significant morbidity and/or mortality (Cantwell et al 2011).

Proteinuria

Proteinuria coinciding with hypertension has been the traditional basis for a diagnosis of pre-eclampsia. However, pre-eclampsia may occur without detectable protein in the urine. Thus a diagnosis should not be dependent on this factor (International Society for the Study of Hypertension in Pregnancy (ISSHP) 2014). Likewise, proteinuria in a normotensive woman should not be discounted, especially if it is profound, because it can precede a notable rise in blood pressure (Lindheimer and Kanter 2010).

Oedema

Oedema can be a common and harmless symptom of pregnancy. However, as a symptom of pre-eclampsia it may be more profound, sudden in onset and especially noticeable in the face (Preeclampsia Foundation 2010).

Epigastric pain

Epigastric pain is an important symptom, especially if it is severe, because it can reflect significant liver damage. Vomiting and tenderness may accompany the pain on palpation. Any woman presenting with epigastric pain after 20 weeks gestation should be suspected of having pre-eclampsia until proven otherwise (Cantwell et al 2011).

Severe headache and visual disturbances

Severe headache and visual disturbances, for example flashing lights, may be related to hypertension or cerebral or retinal oedema (Bewley 2012). Women experiencing headache profound enough to seek medical help should be screened for pre-eclampsia (Cantwell et al 2011).

Potential complications

Pre-eclampsia has the potential to affect numerous systems in the body and may lead to any of the following complications (Bewley 2012):

• Liver damage.
• Clotting abnormalities.
• HELLP syndrome – can lead to disseminated intravascular coagulation (DIC).
• Renal damage.
• Hyperuricaemia.
• Cerebral oedema.
• Cerebral haemorrhage.
• Retinal oedema and blindness.
• Eclampsia.
• Pulmonary oedema.
• Laryngeal oedema.
• Placental ischaemia or infarction.
• Placental abruption.
• Intrauterine growth restriction (IUGR).
• Prematurity of baby.
• Low birth weight.
• Hypoxia leading to neurological complications.
• Stillbirth.

It is important to be aware that both HELLP syndrome and eclampsia may also occur independently of, or precede, hypertension and proteinuria (Action on Pre-eclampsia 2015a, 2015b).

Complete time out activity 1

Consider how you might respond to the following case scenario: A 26-year-old woman who is 34 weeks pregnant with her first baby presents to the emergency department with constant abdominal pain. She has vomited once since arrival and reports some swelling in her hands and feet but states that this is nothing new. Her blood pressure is 142/88mmHg, and her urine shows 1+ of protein and a trace of leukocytes and blood. She is feeling the baby move but perhaps not as much as usual. Compare your proposed actions to the checklist provided in Box 1.

Box 1. Pre-eclampsia assessment checklist

All pregnant women of more than 20 weeks gestation should be assessed for signs of pre-eclampsia. The presence of any warning sign requires midwifery and/or obstetric review and investigations, ideally on a maternity unit.

Warning signs:

• Hypertension (>140/90mmHg).
• Proteinuria (>1+).
• Oedema.
• Visual disturbances.
• Reduced fetal movements – anything less than the usual pattern for the individual woman.

Danger signs:

• Severe hypertension (>160/110mmHg).
• Severe headache, which may be accompanied by visual disturbances.
• Severe epigastric or abdominal pain and/or vomiting.
• Woman appears unwell or to be deteriorating.
• A senior obstetrician must be informed immediately if a woman presents with any danger sign.

If a woman presents with any danger sign, the following should be performed:

• Cannulate the patient.
• Send urgent blood tests (full blood count, urea and electrolytes, liver function tests, uric acid and possibly blood group and antibody screen) to the laboratory.
• Send urine for protein: creatinine ratio (if proteinuria >1+) and mid-stream urine test if leucocytes, blood or nitrites present.
• Monitor fluid balance – intravenous fluids should be administered cautiously and only when prescribed by an anaesthetist or obstetrician.
• Monitor blood pressure closely along with other observations and document on MEOWS (Modified Early Obstetric Warning Score) or other early warning chart if available.
• Prepare to transfer the woman to the maternity unit as soon as possible.

Learning Points

1. Clinical presentations of pre-eclampsia include hypertension, proteinuria, oedema, epigastric pain, severe headache and visual disturbances.
2. Women experiencing headache profound enough to seek medical help should be screened for pre-eclampsia.
3. Hypertension is one of the most common features of pre-eclampsia. Mild hypertension is defined as a systolic blood pressure of 140-149mmHg or a diastolic pressure of 90-99mmHg. A moderate hypertension is 150-159/100-109mmHg and severe hypertension is >160/110mmHg.
4. Complications of pre-eclampsia include: liver damage, clotting abnormalities, HELLP syndrome – can lead to disseminated intravascular coagulation (DIC), renal damage, hyperuricaemia, cerebral oedema, cerebral haemorrhage, retinal oedema and blindness, eclampsia, pulmonary oedema, laryngeal oedema, placental ischaemia or infarction, placental abruption, intrauterine growth restriction (IUGR), prematurity of baby, low birth weight, hypoxia leading to neurological complications, and stillbirth.

Assessment

Pre-eclampsia affects up to 5% of pregnancies in the UK (NHS Choices 2013), and hypertensive disorders of pregnancy affect about 10% of pregnant women worldwide (World Health Organization (WHO) 2011). Despite the prevalence of pre-eclampsia, failure to identify and act on its signs and symptoms is common and has been identified as a significant factor in maternal deaths (Cantwell et al 2011). Early recognition of pre-eclampsia relies on regular and frequent antenatal assessments; the absence of antenatal care has a strong correlation with severe morbidity and death (WHO 2011).

The first step in assessment of pre-eclampsia involves screening pregnant women to identify those at risk. Certain factors are associated with a greater likelihood of developing the condition. Moderate risk factors (NICE 2010) include:

• First pregnancy.
• Previous pre-eclampsia.
• Age 40 years or older.
• Pregnancy interval of more than ten years.
• Body mass index (BMI) of 35 or more at first visit.
• Family history of pre-eclampsia.
• Multiple pregnancy.

There are also a number of high risk factors (NICE 2010):

• Hypertensive disease during a previous pregnancy.
• Chronic kidney disease.
• Autoimmune disease such as systemic lupus erythematosus or antiphospholipid syndrome.
• Type 1 or type 2 diabetes.
• Chronic hypertension.

Subsequent antenatal follow up will depend on the number and type of risk factors identified. For women considered to be high risk, specialist obstetric referral is advised so that an individual plan of assessment can be devised according to their needs (Action on Pre-eclampsia 2004). Those with moderate risk factors should be monitored closely throughout the pregnancy. However, it is important to remember that pre-eclampsia can affect any pregnant woman, and that monitoring should be an integral aspect of all routine antenatal care.

The use of serum markers such as pregnancy-associated plasma protein-A (PAPP-A) and uterine artery Doppler readings have been explored as tools for predicting pre-eclampsia. A combination of maternal history, blood pressure readings, serum marker levels and umbilical artery Doppler readings can be used at 11-13 weeks gestation to provide the most accurate measurement of risk (Poon et al 2010). This has yet to become common practice. NICE (2010) has concluded that more evidence is required before any specific guidelines can be developed.

Learning Points

1. Early assessment and identification of pre-eclampsia reduces the risk of maternal death.
2. Moderate risk factors include: first pregnancy, previous pre-eclampsia, age 40 years or older, pregnancy interval of more than ten years, body mass index (BMI) of 35 or more at first visit, family history of pre-eclampsia, multiple pregnancy.
3. High risk factors include: hypertensive disease during a previous pregnancy, chronic kidney disease, autoimmune disease such as systemic lupus erythematosus or antiphospholipid syndrome, Type 1 or type 2 diabetes and chronic hypertension.
4. Tools for predicting pre-eclampsia include: serum markers such as pregnancy-associated plasma protein-A (PAPP-A), uterine artery Doppler readings, maternal history, blood pressure readings, serum marker levels and umbilical artery Doppler.

Prevention

There is no cure for pre-eclampsia apart from delivery of the baby and placenta; however, there are treatments that may prevent or limit its progression and effects of the condition.

Low dose aspirin: research has shown that low-dose aspirin may be of benefit to women at high risk of developing pre-eclampsia (WHO 2011). It is recommended that women with either one high risk factor of pre-eclampsia, or more than one moderate risk factor of pre-eclampsia, take 75mg of aspirin daily from 12 weeks gestation until the end of the pregnancy (NICE 2010).

Calcium supplementation: calcium supplements significantly reduce the risk of developing pre-eclampsia among women with low dietary intake of the mineral (WHO 2011). This is especially true for those deemed at high risk of developing the condition. A supplement of 1.5-2.0g calcium per day is recommended. Women on iron therapy should avoid taking the two supplements at the same time to avoid any interactions (WHO 2011).

Low molecular weight heparin and other preventive measures: prophylactic low molecular weight heparin may be given to those who have had previous placental complications, such as pre-eclampsia (Magee et al 2014). Bed rest, reduced dietary salt intake, use of diuretics and vitamin D, C and E supplementation have been explored as measures to prevent the development of pre-eclampsia. However, there is not enough evidence to promote their use at present (WHO 2011).

Ongoing assessment

There are several routine assessments that should be performed at each antenatal appointment (NICE 2008), and these should be repeated when a pregnant woman presents with a healthcare concern. A midwife or obstetrician should review all pregnant or postpartum women, regardless of their presenting healthcare problem.

Blood pressure measurement

• It is important to obtain a baseline blood pressure measurement at the first antenatal visit.
• This will provide a benchmark against which to measure future readings and identify those women with pre-existing hypertension.
• Automated blood pressure machines should be validated for use in women with pre-eclampsia because they have been shown to underestimate readings by up to 30mmHg (Magee et al 2014).

Complete time out activity 2

Access the link www.isshp.org/wp-content/uploads/2014/05/rcog.pdfthat outlines how to obtain an accurate blood pressure reading in a pregnant woman. Compare this to your own practice. Are there any differences?

Screening for proteinuria

• Proteinuria is identified typically via an automated reagent strip.
• A result of 1+ or more is considered positive; however, a urinary protein: creatinine ratio (PCR) or a 24-hour urine collection is required to quantify the result.
• A result of 30mg/mmol or more in the PCR or >300mg protein in a 24-hour sample indicates significant proteinuria (NICE 2010).
• As protein excretion can vary throughout the day, a 24-hour collection is considered the most accurate method of measurement (Magee et al 2014).

Assessment of fetal growth and wellbeing

• Poor placental perfusion as a result of pre-eclampsia can compromise fetal development.
• Assessment of fetal wellbeing is an important part of the overall clinical assessment and will influence decisions regarding management.
• Low fundal height measurements can reflect fetal growth restriction, while a reduction in fetal movements may indicate fetal distress (Bewley 2012).

Signs and symptoms

Pre-eclampsia can develop rapidly. An important aspect of care is educating women about the significance of its signs and symptoms and ensuring they know who to contact should they become aware of any. It is important to note that pre-eclampsia may cause few or no symptoms even when advanced.

If any of the above assessments yield abnormal findings, further investigations are warranted. Ideally, the woman should be referred to a maternity assessment unit that is equipped with appropriately trained midwives, advice from senior medical staff, and access to 24-hour laboratory services (Action on Pre-eclampsia 2004).

Learning Points

1. Low-dose aspirin, calcium supplements and prophylactic low molecular weight heparin should be recommended for women at risk of developing pre-eclampsia.
2. Because pre-eclampsia can develop unexpectedly, educating women about the significance of its signs and symptoms and ensuring they know who to contact should they become aware of any symptoms is important.
3. 24-hour urine measurement is considered the most accurate method of measurement for proteinuria.

Investigations

If pre-eclampsia is suspected, further investigations are required to assess maternal and fetal wellbeing and confirm a diagnosis. Laboratory tests are used to measure the effects of pre-eclampsia on various maternal systems and to track progression of the condition. These include (Action on Pre-eclampsia 2009):

• Uric acid.
• Urea and creatinine.
• 24-hour urine measurement or spot creatinine: protein ratio to quantify proteinuria.
• ALT (alanine amino transferase) (liver function test).
• AST (aspartate amino transferase) (liver function test).
• Blood film and platelet count.
• Coagulation studies (performed if disseminated intravascular coagulation (DIC) is suspected).
• The normal ranges for haematological and biochemical values can vary in pregnancy (Cunningham 2010), and these differences should be accounted for when interpreting results.

A combination of tools is used to provide an overall assessment of fetal wellbeing. Cardiotocograph (CTG) monitors the baby’s heartbeat and uterine activity. Ultrasound scans are used to measure fetal growth and amniotic fluid volume. Uterine and/or umbilical artery Doppler results can detect reduced blood flow to the placenta (Bewley 2012).

Abnormal findings may be innocuous or unrelated to pre-eclampsia. Routine antenatal care might then continue in the community, but perhaps with more frequent assessments. If a diagnosis of pre-eclampsia is made, management should follow an obstetrician-led pathway.

Complete time out activity 3

Healthcare professionals providing care to women who are pregnant should be able to identify the signs and symptoms of pre-eclampsia and refer them appropriately. Do you know if staff in your area are equipped with the resources and training necessary to meet this requirement? How might you find this out and what do you think could be done to ensure that they are equipped?

Learning Points

1. Laboratory tests used to measure the effects of pre-eclampsia include uric acid, urea and creatinine, 24-hour urine measurement or spot creatinine, ALT, AST, blood film and platelet count and coagulation studies.
2. Tools used to assess fetal wellbeing include cardiotocograph and ultrasound scans.

Management on diagnosis

Management of women with pre-eclampsia ‘aims at minimising further pregnancy-related complications, avoiding unnecessary prematurity and maximising maternal and infant survival’ (WHO 2011). Clinical decisions, overseen by a named obstetric consultant, are shaped by the severity of the disease, and the gestation of pregnancy, and should involve an integrated plan of care (NICE 2010). The nature of pre-eclampsia provides scope for continued research. Both WHO (2011) and NICE (2010) have highlighted priorities for further investigation, and practice should evolve as advances are made in understanding and management of the condition.

Ongoing assessment

As pre-eclampsia is a dynamic process, both the woman and the fetus should be monitored for signs of deterioration.

• It is the responsibility of the obstetrician to document the frequency and nature of the assessments required, along with thresholds for action.
• Those involved in the woman’s care should be able to identify situations where additional monitoring is necessary, for example reduced fetal movements, vaginal bleeding, abdominal pain or a deterioration in maternal condition (NICE 2010).
• The obstetrician should be informed in these circumstances, or if any fetal assessments yield abnormal results.

Controlling hypertension

Hypertension serves as a warning sign for pre-eclampsia, and if severe may cause serious or life-threatening complications such as cerebrovascular haemorrhage (Impey and Child 2012).

• There is a consensus that severe hypertension requires treatment. However, the evidence is less clear with respect to mild and moderate hypertension (NICE 2010, WHO 2011).
• The antihypertensive medications prescribed most commonly are labetalol, methyldopa, nifedipine and hydralazine (NICE 2010, WHO 2011).
• The choice of drug, dosage and timing depends on the clinical situation and should be decided by senior medical staff in line with hospital policy.
• Other antihypertensive medications that may be prescribed include atenolol, captopril, enalapril and metoprolol (NICE 2010).
• The parameters for drug administration should be documented clearly.
• It is the responsibility of those administering the medications to be aware of these and to use their clinical judgement appropriately.
• Medical staff should be informed if medications are not producing the desired effect, for example the woman remains hypertensive or alternatively becomes hypotensive.

Preventing or controlling seizures

• In severe pre-eclampsia, magnesium sulfate (an anticonvulsant) can be administered to prevent or treat eclamptic seizures (Box 2).
• Any woman receiving magnesium sulfate requires close monitoring and one-to-one care. Magnesium sulfate levels may accumulate to the point of toxicity, which can lead to muscle paralysis, respiratory arrest and cardiac arrest (Salisbury NHS Foundation Trust 2015).
• Serum levels of the drug will need to be assessed regularly along with maternal patellar reflexes, as absence of these reflexes can be one of the first signs of toxicity (Bewley 2012).

Complete time out activity 4

Consider the management of eclampsia outlined in Box 2. Is this an emergency situation that you might encounter in your area of work? If so, do you feel prepared to respond appropriately? What changes could you make to ensure that you are?

Box 2. Management of eclampsia

Eclampsia is a rare but life-threatening complication of pre-eclampsia, characterised by the sudden onset of tonic and/or clonic seizures. It is thought to be caused by intense cerebral vasospasm and oedema leading to hypoxia (Bewley 2012). In the event of a seizure, the following measures should be taken where possible until obstetric and/or midwifery assistance arrives and the woman can be transferred to a maternity unit:

• Get help. Be clear that it is an obstetric emergency and that an obstetric team and anaesthetist are required immediately.
• Request a crash trolley and magnesium sulfate or eclampsia boxes (containing necessary drugs, specimen bottles and paper work) if available.
• Do not leave the woman. Most seizures are self-limiting.
• Secure the woman’s airway. If pregnant, ensure the woman is tilted towards her left side by placing a wedge under her right hip. This displaces the uterus and prevents aortocaval compression, which can impair circulation (Bewley 2012).
• Check breathing. Give high flow oxygen, assess saturations and ventilate if necessary.
• Check circulation. Assess pulse and blood pressure. If there is no pulse, make an adult cardiac arrest call in addition to an obstetric emergency call.
• Gain intravenous (IV) access and administer fluids slowly, for example Hartmans at 80mL/hour. Avoid fluid overload.
• Monitor blood pressure, pulse, oxygen saturations, respiratory rate and level of consciousness every five minutes. Document on MEOWS (Modified Early Obstetric Warning Score) chart, if available.
• Send urgent blood tests to the laboratory: full blood count, urea and electrolytes, liver function tests, uric acid, clotting screen and blood group and antibody screen. Send urine sample for protein: creatinine ratio and midstream specimen of urine (MSU) test. The appropriate blood and urine bottles are usually provided in an eclampsia box, if available.
• Magnesium sulfate should be administered as soon as possible to prevent further seizures. The regimen should follow local policy and the decision to administer it should be made by a senior obstetrician. Typically this consists of a loading dose of 4g administered as an intravenous (IV) bolus over 5-10 minutes, followed by an infusion of 1g per hour over 24 hours (NICE 2010).
• Insert urinary catheter and monitor urine output.
• Perform an electrocardiogram.

Ongoing management will focus on stabilising the woman, preventing further seizures, controlling blood pressure, monitoring fetal wellbeing and making a decision to deliver the baby, if the woman is pregnant.

Corticosteroids

• If premature delivery (<36 weeks) is anticipated, then corticosteroids may be administered to promote fetal lung maturation.
• Betamethasone is the drug of choice and two doses are given 24 hours apart (NICE 2010).
• Delivery of the baby may be deferred until a course of corticosteroids is completed, if the benefits are thought to outweigh the risks.

Fluid restriction

Fluid restriction is an important consideration in pre-eclampsia.

• Impaired renal function can make women especially susceptible to fluid overload, leading to complications such as pulmonary oedema (Impey and Child 2012).
• Fluid intake and urinary output need to be monitored and a urinary catheter may be indicated.
• Fluid intake is restricted usually to 80mL/hour, although the clinical circumstances may dictate otherwise, for example if the woman is haemorrhaging (Bewley 2012).
• Oliguria is signalled by a urine output below 25mL/hour and requires further investigation. An anaesthetist should be informed urgently if the output is less than 10mL/hour (Salisbury NHS Foundation Trust 2015).

Thromboprophylaxis

Pre-eclampsia is a significant risk factor for venous thromboembolism. All women diagnosed with the disorder require a risk assessment and prophylactic treatment (Lowe et al 2014).

Learning Points

1. Management of women with pre-eclampsia ‘aims at minimising further pregnancy-related complications, avoiding unnecessary prematurity and maximising maternal and infant survival’.
2. Hypertension as a result of pre-eclampsia, if severe, can cause life-threatening complications, such as cerebrovascular haemorrhage. Medical staff should be informed about the side effects of any drugs given.
3. If premature delivery is anticipated, then corticosteroids may be administered to promote fetal lung maturation.
4. Betamethasone is the drug of choice and two doses are given 24 hours apart.

Decision to deliver

Delivery of the baby and placenta is the only cure for pre-eclampsia. Deciding on the most appropriate time depends on factors such as the woman’s gestation, maternal and fetal wellbeing, availability of neonatal intensive care beds, and whether corticosteroids have been administered. The choice of either caesarean section or induction of labour will depend on the clinical circumstances, with the potential risks and benefits taken into account. Delivery should take place on a unit that is equipped to provide the appropriate care, with access to a neonatal ICU (NICE 2010).

Labour

• During labour the condition of the woman and the fetus should be monitored closely.
• Epidural analgesia is often recommended because it limits the effects of pain-related stress, and acts directly to lower blood pressure.
• Preloading women with fluids to prevent hypotension should be avoided, because of the threat of fluid overload (Magee et al 2014).
• An epidural may be contraindicated in cases of severe thrombocytopaenia because it carries a small risk of bleeding into the epidural space.
• Platelet levels less than 75 x 109/L require careful consideration by an anaesthetist (The Association of Anaesthetists of Great Britain and Ireland et al 2013).
• A prolonged second stage of labour is discouraged, especially if control of blood pressure is proving difficult. For a severely hypertensive woman, the obstetrician may choose to perform an operative delivery in the second stage to reduce the risk of raised intracranial pressure and cerebral haemorrhage (Impey and Child 2012).
• The use of ergometrine should be avoided because it can lead to an increase in blood pressure. Syntocinon rather than syntometrine is recommended for the third stage of labour (Royal College of Obstetricians and Gynaecologists 2010).

Postnatal management

Following delivery of the baby, the woman’s condition can be expected to improve and resolve. However, it is possible for pre-eclampsia to first present or initially worsen in the postnatal period, in which case blood pressure has a tendency to peak on day five post-birth (Impey and Child 2012). Continued assessment and management is necessary. The use of non-steroidal anti-inflammatory drugs may be contraindicated because liver enzyme levels can increase and thrombocytopaenia may worsen initially (Lowe et al 2014).

On discharge from hospital, a written plan clearly documenting requirements for follow-up care is essential. The plan should include frequency of blood pressure monitoring, parameters for continued antihypertensive treatment, and specific actions to be taken if hypertension or proteinuria persists.

It is important that the woman understands the implications of pre-eclampsia on her future health. Pre-eclampsia is associated with an increased risk of developing essential hypertension and cardiovascular disease in the longer term. She will need to be monitored more closely in future pregnancies because the recurrence rate is 16-25%, depending on the severity of her experience (Bellamy et al 2007). Maintaining a healthy weight will help to reduce these risks (Magee et al 2014).

Learning Points

1. The use of non-steroidal anti-inflammatory drugs may be contraindicated because liver enzyme levels can increase and thrombocytopaenia may worsen initially.
2. Future pregnancies should be monitored closely because of the risk of developing essential hypertension and cardiovascular disease. Maintaining a healthy weight will help to reduce the risks.

Conclusions

• Pre-eclampsia is a complex, variable and potentially life-threatening condition. Early detection and appropriate management are crucial.
• It is imperative that pregnant women, and those involved in their care, understand the significance of pre-eclampsia’s signs and symptoms.
• A multidisciplinary effort overseen by a lead obstetrician ensures the best outcome for the woman and her baby.
• In addition to pre-eclampsia, the woman is susceptible to both physical and emotional stress related to the pregnancy and birth.
• It can be a traumatic experience for her, possibly compounded by the distress of separation from her newborn baby. She is likely to require significant emotional as well as physical care.
• Pre-eclampsia has implications for the woman’s future health and she should be counselled in respect of these.
• The nature of pre-eclampsia provides scope for continued research.
• Priorities for further investigation have been emphasised, and best practice should evolve as advances are made in understanding and managing the condition.

Diagnosing, assessing and managing pre-eclampsia

This learning module has been accredited by the Royal College of Nursing and was last updated in 2016.

All modules are subject to external double-blind peer review and checked for plagiarism using automated software.

Duration: 01:00:00 Type: CPD modules Level: Qualified Nurses

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Author

Layla Lavallee, Research midwife, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, England.

Short description

Discover how to identify and manage pre-eclampsia based in clinical guidelines developed in the UK and worldwide.

Detailed description

Pre-eclampsia is a complex and unpredictable disorder that may occur during pregnancy. Its presentation ranges from mild to severe, and the condition may lead to the death of the mother and/or the baby in extreme cases. The earlier the disorder is detected and managed, the better the outcome. This learning module provides an outline of the disorder and its management, within the framework of UK and international guidelines. A series of suggested activities encourages the reader to reflect on the information provided within the context of their practice.

Acronyms

ALT: alanine amino transferase

AST: aspartate amino transferase

CTG: cardiotocograph

DIC: disseminated intravascular coagulation

HELLP: haemolysis, elevated liver enzymes and low-platelet count

ICU: intensive care unit

ISSHP: International Society for the Study of Hypertension in Pregnancy

IUGR: intrauterine growth restriction

NHS: National Health Service

NICE: National Institute for Health and Care Excellence

NMC: Nursing and Midwifery Council

PAPP-A: pregnancy-associated plasma protein-A

WHO: World Health Organization

Glossary

Cerebral haemorrhage: bleeding from a ruptured blood vessel in the brain.

Cerebral oedema: a serious condition that develops as a result of accumulation of excessive fluid in the intracellular and/or extracellular spaces of the brain.

Disseminated intravascular coagulation: a life-threatening clotting disorder characterised by a rapid consumption of clotting factors which leads to microvascular thrombi and bleeding.

HELLP syndrome: a life-threatening complication of pregnancy characterised by haemolysis, elevated liver enzymes and low platelet count. It is considered to be a variant of pre-eclampsia and usually occurs during the later stages of pregnancy, or after childbirth.

Intrauterine growth restriction (IUGR): a condition in which a baby's growth slows or ceases when it is in the uterus. Also called intrauterine growth retardation.

Laryngeal oedema: a frequent complication of intubation. It often presents shortly after extubation as post-extubation stridor and results from damage to the mucosa of the larynx.

Placental abruption: a condition in which the placenta starts to separate from the inner wall of the uterus before the baby is born.

Placental infarction: an area of dead tissue in the placenta caused by the interruption in blood flow between the placenta and the baby. Small infarctions occur normally in the placenta as the pregnancy progresses, and do not generally affect the pregnancy.

Pre-eclampsia: a serious condition developing in late pregnancy characterised by a sudden rise in blood pressure, generalised oedema, proteinuria, severe headache, and visual disturbances that may result in eclampsia (convulsive or coma state) if untreated.

Proteinuria: excessive amounts of protein in the urine. It is usually identified via an automated reagent strip, in which a result of 1+ or more is considered positive.

Vasospasm: a sudden contraction of a blood vessel, reducing its diameter and blood flow.

References

Action on Pre-eclampsia (2004) PRECOG: The Pre-eclampsia Community Guideline. action-on-pre-eclampsia.org.uk/wp-content/uploads/2012/07/PRECOG-Community-Guideline.pdf (Last accessed: June 4 2015.)

Action on Pre-eclampsia (2009) Pre-eclampsia Day Assessment Unit Guideline for Midwives (PRECOG 2). action-on-pre-eclampsia.org.uk/wp-content/uploads/2012/07/PRECOG-Day-Assessment.pdf (Last accessed: June 4 2015.)

Action on Pre-eclampsia (2015a) Eclampsia. action-on-pre-eclampsia.org.uk/pre-eclampsia-information/fact-sheet-3-eclampsia/ (Last accessed June 4 2015.)

Action on Pre-eclampsia (2015b) HELLP Syndrome. action-on-pre-eclampsia.org.uk/pre-eclampsia-information/hellp/ (Last accessed: June 4 2015.)

Bellamy L, Casas JP, Hingorani AD, Williams DJ (2007) Pre-eclampsia and risk of cardiovascular disease and cancer in later life: systematic review and meta-analysis. British Medical Journal. doi:10.1136/bmj.39335.385301.

Bewley C (2012) Hypertensive disorders of pregnancy. In Macdonald S, Magill-Cuerden J (Eds) Mayes’ Midwifery. 14th edition. Baillière Tindall Elsevier, Edinburgh, 787-798.

Cantwell R, Clutton-Brock T, Cooper G et al (2011) Saving Mother’s Lives: reviewing maternal deaths to make motherhood safer 2006-2008. The Eighth Report on Confidential Enquiries into Maternal Deaths in the United Kingdom. British Journal of Obstetrics and Gynaecology. 118, Suppl 1, 1-203.

Cunningham F (2010) Laboratory values in normal pregnancy. In Queenan JT, Hobbins JC, Spong CY (Eds) Protocols for High-Risk Pregnancies: An Evidence-Based Approach. Fifth edition. Blackwell Publishing, Oxford, 587-595.

Impey L, Child T (2012) Obstetrics and Gynaecology. Fourth edition. Wiley-Blackwell, Chichester.

International Society for the Study of Hypertension in Pregnancy (2014) The classification, diagnosis, and management of the hypertensive disorders of pregnancy: a revised statement from the ISSHP. Pregnancy Hypertension: An International Journal of Women’s Cardiovascular Health. 4, 97-104. MEDLINE • CROSSREF

Lindheimer M, Kanter D (2010) Interpreting abnormal proteinuria in pregnancy: the need for a more pathophysiological approach. Obstetrics and Gynecology. 115, 2 Pt 1, 365-375. MEDLINE • CROSSREF

Lowe SA, Bowyer L, Lust K et al (2014) The SOMANZ Guideline for the Management of Hypertensive Disorders of Pregnancy. somanz.org/documents/HTPregnancyGuidelineJuly2014.pdf (Last accessed: June 4 2015.)

Magee LA, Pels A, Helewa M et al (2014) Diagnosis, evaluation, and management of the hypertensive disorders of pregnancy: executive summary. Journal of Obstetrics and Gynaecology Canada. 36, 5, 416-438. MEDLINE

National Institute for Health and Care Excellence (2008) Antenatal Care. Clinical guideline No. 62. NICE, London.

National Institute for Health and Care Excellence (2010) Hypertension in Pregnancy: The Management of Hypertensive Disorders during Pregnancy. Clinical guideline No. 107. NICE, London.

NHS Choices (2013) Pre-eclampsia. nhs.uk/conditions/pre-eclampsia/Pages/Introduction.aspx (Last accessed: June 4 2015.)

Nursing and Midwifery Council (2015) The Code: Professional Standards of Practice and Behaviour for Nurses and Midwives. NMC, London.

Poon L, Stratieva V, Piras S, Piri S, Nikolaides KH (2010) Hypertensive disorders in pregnancy: combined screening by uterine artery Doppler, blood pressure and serum PAPP-A at 11-13 weeks. Prenatal Diagnosis. 30, 3, 216-223.MEDLINE

Preeclampsia Foundation (2010) Signs and Symptoms. preeclampsia.org/health-information/sign-symptoms (Last accessed: June 4 2015.)

Royal College of Obstetricians and Gynaecologists (2010) The Management of Severe Preclampsia/Eclampsia. Guideline No.10(A). isshp.org/wp-content/uploads/2014/05/rcog.pdf (Last accessed: June 5 2015.)

NHS Foundation Trust (2015) Management of Hypertension in Pregnancy. icid.salisbury.nhs.uk/CLINICALMANAGEMENT/MATERNITYNEONATAL/Pages/ManagementofHypertensioninPregnancy.aspx (Last accessed: June 5 2015.)

The Association of Anaesthetists of Great Britain and Ireland, The Obstetric Anaesthetists’ Association, Regional Anaesthesia UK (2013) Regional anaesthesia and patients with abnormalities of coagulation. Anaesthesia. 68, 9, 966-972. MEDLINE • CROSSREF

World Health Organization (2011) WHO Recommendations for Prevention and Treatment of Pre-eclampsia and Eclampsia. WHO, Geneva.