Symptoms of pre-eclampsia

1.1.1.

Advise pregnant women to see a healthcare professional immediately if they experience symptoms of pre-eclampsia. Symptoms include:

• severe headache
• problems with vision, such as blurring or flashing before the eyes
• severe pain just below the ribs
• vomiting
• sudden swelling of the face, hands or feet.

See the NICE guideline on antenatal care for advice on risk factors and symptoms of pre-eclampsia. [2010, amended 2019]

Antiplatelet agents

1.1.2.

Advise pregnant women at high risk of pre-eclampsia to take 75–150 mg of aspirin^[1] daily from 12 weeks until the birth of the baby. Women at high risk are those with any of the following:

• 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. [2010, amended 2019]

1.1.3.

Advise pregnant women with more than 1 moderate risk factor for pre-eclampsia to take 75–150 mg of aspirin^[1] daily from 12 weeks until the birth of the baby. Factors indicating moderate risk are:

• first pregnancy
• age 40 years or older
• pregnancy interval of more than 10 years
• body mass index (BMI) of 35 kg/m² or more at first visit
• family history of pre-eclampsia
• multi-fetal pregnancy. [2010, amended 2019]

Other pharmaceutical agents

1.1.4.

Do not use the following to prevent hypertensive disorders during pregnancy:

• nitric oxide donors
• progesterone
• diuretics
• low molecular weight heparin. [2010]

Nutritional supplements

1.1.5.

Do not recommend the following supplements solely with the aim of preventing hypertensive disorders during pregnancy:

• magnesium
• folic acid
• antioxidants (vitamins C and E)
• fish oils or algal oils
• garlic. [2010]

Diet

1.1.6.

Do not recommend salt restriction during pregnancy solely to prevent gestational hypertension or pre-eclampsia. [2010]

Lifestyle

1.1.7.

Give the same advice on rest, exercise and work to women with chronic hypertension or at risk of hypertensive disorders during pregnancy as healthy pregnant women. See the NICE guideline on antenatal care. [2010, amended 2019]

Diabetes

1.1.8.

For women with pre-existing diabetes or gestational diabetes, see the NICE guideline on diabetes in pregnancy. [2019]

Pre-pregnancy advice

1.3.1.

Offer women with chronic hypertension referral to a specialist in hypertensive disorders of pregnancy to discuss the risks and benefits of treatment. [2010, amended 2019]

1.3.2.

Advise women who take angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers^[2] (ARBs):

• that there is an increased risk of congenital abnormalities if these drugs are taken during pregnancy
• to discuss alternative antihypertensive treatment with the healthcare professional responsible for managing their hypertension, if they are planning pregnancy
• to discuss alternative treatment with the healthcare professional responsible for managing their condition, if ACE inhibitors or ARBs are being taken for other conditions such as renal disease. [2010, amended 2019]

1.3.3.

Stop antihypertensive treatment in women taking ACE inhibitors or ARBs if they become pregnant (preferably within 2 working days of notification of pregnancy) and offer alternatives. [2010]

1.3.4.

Advise women who take thiazide or thiazide-like diuretics:

• that there may be an increased risk of congenital abnormalities and neonatal complications if these drugs are taken during pregnancy
• to discuss alternative antihypertensive treatment with the healthcare professional responsible for managing their hypertension, if they are planning pregnancy. [2010, amended 2019]

1.3.5.

Advise women who take antihypertensive treatments other than ACE inhibitors, ARBs, thiazide or thiazide-like diuretics that the limited evidence available has not shown an increased risk of congenital malformation with such treatments. [2010, amended 2019]

Treatment of chronic hypertension

1.3.6.

Offer pregnant women with chronic hypertension advice on:

• weight management
• exercise
• healthy eating
• lowering the amount of salt in their diet.

Provide this advice in line with the NICE guideline on hypertension in adults: diagnosis and treatment. [2019]

1.3.7.

Continue with existing antihypertensive treatment if safe in pregnancy, or switch to an alternative treatment, unless:

• sustained systolic blood pressure is less than 110 mmHg or
• sustained diastolic blood pressure is less than 70 mmHg or
• the woman has symptomatic hypotension. [2019]

1.3.8.

Offer antihypertensive treatment to pregnant women who have chronic hypertension and who are not already on treatment if they have:

• sustained systolic blood pressure of 140 mmHg or higher or
• sustained diastolic blood pressure of 90 mmHg or higher. [2019]

1.3.9.

When using medicines to treat hypertension in pregnancy, aim for a target blood pressure of 135/85 mmHg. [2019]

1.3.10.

Consider labetalol to treat chronic hypertension in pregnant women. Consider nifedipine^[3] for women in whom labetalol is not suitable, or methyldopa if both labetalol and nifedipine^[3] are not suitable. Base the choice on any pre-existing treatment, side-effect profiles, risks (including fetal effects) and the woman’s preference. [2019]

1.3.11.

Offer pregnant women with chronic hypertension aspirin^[1] 75–150 mg once daily from 12 weeks. [2019]

1.3.12.

Offer placental growth factor (PlGF)-based testing to help rule out pre-eclampsia between 20 weeks and up to 35 weeks of pregnancy, if women with chronic hypertension are suspected of developing pre-eclampsia. (See the NICE diagnostics guidance on PlGF-based testing to help diagnose suspected pre-eclampsia). [2019]

Antenatal appointments

1.3.13.

In women with chronic hypertension, schedule additional antenatal appointments based on the individual needs of the woman and her baby. This may include:

• weekly appointments if hypertension is poorly controlled
• appointments every 2 to 4 weeks if hypertension is well-controlled. [2010, amended 2019]

Timing of birth

1.3.14.

Do not offer planned early birth before 37 weeks to women with chronic hypertension whose blood pressure is lower than 160/110 mmHg, with or without antihypertensive treatment, unless there are other medical indications. [2010, amended 2019]

1.3.15.

For women with chronic hypertension whose blood pressure is lower than 160/ 110 mmHg after 37 weeks, with or without antihypertensive treatment, timing of birth and maternal and fetal indications for birth should be agreed between the woman and the senior obstetrician. [2010]

1.3.16.

If planned early birth is necessary (see recommendation 1.5.7), offer a course of antenatal corticosteroids and magnesium sulfate if indicated, in line with the NICE guideline on preterm labour and birth. [2010, amended 2019]

Postnatal investigation, monitoring and treatment

1.3.17.

In women with chronic hypertension who have given birth, measure blood pressure:

• daily for the first 2 days after birth
• at least once between day 3 and day 5 after birth
• as clinically indicated if antihypertensive treatment is changed after birth. [2010]

1.3.18.

In women with chronic hypertension who have given birth:

• aim to keep blood pressure lower than 140/90 mmHg
• continue antihypertensive treatment, if required (see section 1.9 for choice of antihypertensive during the postnatal period)
• offer a review of antihypertensive treatment 2 weeks after the birth, with their GP or specialist. [2010, amended 2019]

1.3.19.

If a woman has taken methyldopa to treat chronic hypertension during pregnancy, stop within 2 days after the birth and change to an alternative antihypertensive treatment (see section 1.9 for choice of antihypertensive during the postnatal period). [2010, amended 2019]

1.3.20.

Offer women with chronic hypertension a medical review 6–8 weeks after the birth with their GP or specialist as appropriate. [2010, amended 2019]

Assessment and treatment of gestational hypertension

1.4.1.

In women with gestational hypertension, a full assessment should be carried out in a secondary care setting by a healthcare professional who is trained in the management of hypertensive disorders of pregnancy. [2010, amended 2019]

1.4.2.

In women with gestational hypertension, take account of the following risk factors that require additional assessment and follow-up:

• nulliparity
• age 40 years or older
• pregnancy interval of more than 10 years
• family history of pre-eclampsia
• multi-fetal pregnancy
• BMI of 35 kg/m² or more
• gestational age at presentation
• previous history of pre-eclampsia or gestational hypertension
• pre-existing vascular disease
• pre-existing kidney disease. [2010]

1.4.3.

Offer women with gestational hypertension the tests and treatment listed in table 1. [2019]

Table 1

Management of pregnancy with gestational hypertension.

1.4.4.

Offer placental growth factor (PIGF)-based testing to help rule out pre-eclampsia in women presenting with suspected pre-eclampsia (for example, with gestational hypertension) between 20 weeks and up to 35 weeks of pregnancy. (See the NICE diagnostics guidance on PIGF-based testing to help diagnose suspected pre-eclampsia.) [2019]

1.4.5.

Consider labetalol to treat gestational hypertension. Consider nifedipine^[3] for women in whom labetalol is not suitable, and methyldopa if labetalol or nifedipine^[3] are not suitable. Base the choice on side-effect profiles, risk (including fetal effects) and the woman’s preferences. [2010, amended 2019]

1.4.6.

Do not offer bed rest in hospital as a treatment for gestational hypertension. [2010]

Timing of birth

1.4.7.

Do not offer planned early birth before 37 weeks to women with gestational hypertension whose blood pressure is lower than 160/110 mmHg, unless there are other medical indications. [2010, amended 2019]

1.4.8.

For women with gestational hypertension whose blood pressure is lower than 160/110 mmHg after 37 weeks, timing of birth, and maternal and fetal indications for birth should be agreed between the woman and the senior obstetrician. [2010, amended 2019]

1.4.9.

If planned early birth is necessary (see recommendation 1.5.7), offer a course of antenatal corticosteroids and magnesium sulfate if indicated, in line with the NICE guideline on preterm labour and birth. [2010, amended 2019]

Postnatal investigation, monitoring and treatment

1.4.10.

In women with gestational hypertension who have given birth, measure blood pressure:

• daily for the first 2 days after birth
• at least once between day 3 and day 5 after birth
• as clinically indicated if antihypertensive treatment is changed after birth. [2010]

1.4.11.

In women with gestational hypertension who have given birth:

• continue antihypertensive treatment if required (see section 1.9 for choice of antihypertensive during the postnatal period)
• advise women that the duration of their postnatal antihypertensive treatment will usually be similar to the duration of their antenatal treatment (but may be longer)
• reduce antihypertensive treatment if their blood pressure falls below 130/80 mmHg. [2010, amended 2019]

1.4.12.

If a woman has taken methyldopa to treat gestational hypertension, stop within 2 days after the birth and change to an alternative treatment if necessary (see section 1.9 for choice of antihypertensive during the postnatal period). [2010, amended 2019]

1.4.13.

For women with gestational hypertension who did not take antihypertensive treatment and have given birth, start antihypertensive treatment if their blood pressure is 150/100 mmHg or higher. [2010, amended 2019]

1.4.14.

Write a care plan for women with gestational hypertension who have given birth and are being transferred to community care that includes all of the following:

• who will provide follow-up care, including medical review if needed
• frequency of blood pressure monitoring needed
• thresholds for reducing or stopping treatment
• indications for referral to primary care for blood pressure review. [2010]

1.4.15.

Offer women who have had gestational hypertension and who remain on antihypertensive treatment, a medical review with their GP or specialist 2 weeks after transfer to community care. [2010, amended 2019]

1.4.16.

Offer all women who have had gestational hypertension a medical review with their GP or specialist 6–8 weeks after the birth. [2010, amended 2019]

Assessing pre-eclampsia

1.5.1.

Assessment of women with pre-eclampsia should be performed by a healthcare professional trained in the management of hypertensive disorders of pregnancy. [2010, amended 2019]

1.5.2.

Carry out a full clinical assessment at each antenatal appointment for women with pre-eclampsia, and offer admission to hospital for surveillance and any interventions needed if there are concerns for the wellbeing of the woman or baby. Concerns could include any of the following:

• sustained systolic blood pressure of 160 mmHg or higher
• any maternal biochemical or haematological investigations that cause concern, for example, a new and persistent:

  -

  rise in creatinine (90 micromol/litre or more, 1 mg/100 ml or more) or

  -

  rise in alanine transaminase (over 70 IU/litre, or twice upper limit of normal range) or

  -

  fall in platelet count (under 150,000/microlitre)

• signs of impending eclampsia
• signs of impending pulmonary oedema
• other signs of severe pre-eclampsia
• suspected fetal compromise
• any other clinical signs that cause concern. [2019]

1.5.3.

Consider using either the fullPIERS or PREP-S validated risk prediction models to help guide decisions about the most appropriate place of care (such as the need for in utero transfer) and thresholds for intervention. [2019]

1.5.4.

When using a risk prediction model, take into account that:

• fullPIERS is intended for use at any time during pregnancy
• PREP-S is intended for use only up to 34 weeks of pregnancy
• fullPIERS and PREP-S models do not predict outcomes for babies. [2019]

Treatment of pre-eclampsia

1.5.5.

Offer women with pre-eclampsia the tests and treatments listed in table 2. [2019]

Table 2

Management of pregnancy with pre-eclampsia.

1.5.6.

Offer labetalol to treat hypertension in pregnant women with pre-eclampsia. Offer nifedipine^[3] for women in whom labetalol is not suitable, and methyldopa if labetalol or nifedipine^[3] are not suitable. Base the choice on any pre-existing treatment, side-effect profiles, risks (including fetal effects) and the woman’s preference. [2010, amended 2019]

Timing of birth

1.5.7.

Record maternal and fetal thresholds for planned early birth before 37 weeks in women with pre-eclampsia. Thresholds for considering planned early birth could include (but are not limited to) any of the following known features of severe pre-eclampsia:

• inability to control maternal blood pressure despite using 3 or more classes of antihypertensives in appropriate doses
• maternal pulse oximetry less than 90%
• progressive deterioration in liver function, renal function, haemolysis, or platelet count
• ongoing neurological features, such as severe intractable headache, repeated visual scotomata, or eclampsia
• placental abruption
• reversed end-diastolic flow in the umbilical artery doppler velocimetry, a non-reassuring cardiotocograph, or stillbirth.

Other features not listed above may also be considered in the decision to plan early birth.[2019]

1.5.8.

Involve a senior obstetrician in any decisions on timing of birth for women with pre-eclampsia. [2010, amended 2019]

1.5.9.

Discuss with the anaesthetic team if birth is planned in a woman with pre-eclampsia. [2010, amended 2019]

1.5.10.

Discuss with the neonatal team if birth is planned in a woman with pre-eclampsia, and neonatal complications are anticipated. [2010, amended 2019]

1.5.11.

Offer intravenous magnesium sulfate and a course of antenatal corticosteroids if indicated, if early birth is planned for women with preterm pre-eclampsia, in line with the NICE guideline on preterm labour and birth. [2010, amended 2019]

1.5.12.

Decide on timing of birth in women with pre-eclampsia as recommended in table 3. [2019]

Table 3

Timing of birth in women with pre-eclampsia.

Postnatal investigation, monitoring and treatment (including after discharge from critical care)

Fetal monitoring in chronic hypertension

1.6.1.

In women with chronic hypertension, carry out an ultrasound for fetal growth and amniotic fluid volume assessment, and umbilical artery doppler velocimetry at 28 weeks, 32 weeks and 36 weeks. [2010, amended 2019]

1.6.2.

In women with chronic hypertension, only carry out cardiotocography if clinically indicated. [2010, amended 2019]

Fetal monitoring in gestational hypertension

1.6.3.

In women with gestational hypertension, carry out an ultrasound for fetal growth and amniotic fluid volume assessment and umbilical artery doppler velocimetry at diagnosis and if normal repeat every 2 to 4 weeks, if clinically indicated. [2010, amended 2019]

1.6.4.

In women with gestational hypertension, only carry out cardiotocography if clinically indicated. [2010, amended 2019]

Fetal monitoring in pre-eclampsia or severe gestational hypertension

1.6.5.

Carry out cardiotocography at diagnosis of pre-eclampsia or severe gestational hypertension. [2010]

1.6.6.

If conservative management of pre-eclampsia or severe gestational hypertension is planned, carry out all the following tests at diagnosis:

• ultrasound for fetal growth and amniotic fluid volume assessment
• umbilical artery doppler velocimetry. [2010]

1.6.7.

If the results of all fetal monitoring are normal in women with pre-eclampsia or severe gestational hypertension, do not routinely repeat cardiotocography unless clinically indicated. [2010, amended 2019]

1.6.8.

In women with pre-eclampsia or severe gestational hypertension, repeat cardiotocography if any of the following occur:

• the woman reports a change in fetal movement
• vaginal bleeding
• abdominal pain
• deterioration in maternal condition. [2010]

1.6.9.

In women with pre-eclampsia or severe gestational hypertension, repeat ultrasound for fetal growth and amniotic fluid volume assessment or umbilical artery doppler velocimetry every 2 weeks, with subsequent surveillance and monitoring determined by the findings of these scans. [2010, amended 2019]

1.6.10.

For women with pre-eclampsia or severe gestational hypertension, write a care plan that includes all of the following:

• the timing and nature of future fetal monitoring
• fetal indications for birth and if and when antenatal corticosteroids should be given
• plans for discussion with neonatal paediatricians and obstetric anaesthetists. [2010, amended 2019]

Women who need additional fetal monitoring

1.6.11.

Carry out an ultrasound for fetal growth and amniotic fluid volume assessment and umbilical artery doppler velocimetry starting at between 28 and 30 weeks (or at least 2 weeks before previous gestational age of onset if earlier than 28 weeks) and repeating 4 weeks later in women with previous:

• severe pre-eclampsia
• pre-eclampsia that resulted in birth before 34 weeks
• pre-eclampsia with a baby whose birth weight was less than the 10^th centile
• intrauterine death
• placental abruption. [2010]

1.6.12.

In women who need additional fetal monitoring (see recommendation 1.6.11), carry out cardiotocography only if clinically indicated. [2010, amended 2019]

Blood pressure

1.7.3.

During labour, measure blood pressure:

• hourly, in women with hypertension
• every 15–30 minutes until blood pressure is less than 160/110 mmHg in women with severe hypertension. [2010, amended 2019]

1.7.4.

Continue use of antenatal antihypertensive treatment during labour. [2010]

Haematological and biochemical monitoring

1.7.5.

Determine the need for haematological and biochemical tests during labour in women with hypertension using the same criteria as in the antenatal period even if regional analgesia is being considered. [2010]

Care during epidural analgesia

1.7.6.

Do not preload women who have severe pre-eclampsia with intravenous fluids before establishing low-dose epidural analgesia or combined spinal epidural analgesia. [2010, amended 2019]

Management of second stage of labour

1.7.7.

Do not routinely limit the duration of the second stage of labour in women with controlled hypertension. [2010, amended 2019]

1.7.8.

Consider operative or assisted birth in the second stage of labour for women with severe hypertension whose hypertension has not responded to initial treatment. [2010, amended 2019]

Anticonvulsants

1.8.1.

If a woman in a critical care setting who has severe hypertension or severe pre-eclampsia has or previously had an eclamptic fit, give intravenous magnesium sulfate. [2010]

1.8.2.

Consider giving intravenous magnesium sulfate to women with severe pre-eclampsia who are in a critical care setting if birth is planned within 24 hours. [2010]

1.8.3.

Consider the need for magnesium sulfate treatment, if 1 or more of the following features of severe pre-eclampsia is present:

• ongoing or recurring severe headaches
• visual scotomata
• nausea or vomiting
• epigastric pain
• oliguria and severe hypertension
• progressive deterioration in laboratory blood tests (such as rising creatinine or liver transaminases, or falling platelet count). [2010, amended 2019]

1.8.4.

Use the Collaborative Eclampsia Trial regimen for administration of magnesium sulfate^[4]:

• A loading dose of 4 g should be given intravenously over 5 to 15 minutes, followed by an infusion of 1 g/hour maintained for 24 hours. If the woman has had an eclamptic fit, the infusion should be continued for 24 hours after the last fit.
• Recurrent fits should be treated with a further dose of 2–4 g given intravenously over 5 to 15 minutes. [2010, amended 2019]

1.8.5.

Do not use diazepam, phenytoin or other anticonvulsants as an alternative to magnesium sulfate in women with eclampsia. [2010, amended 2019]

Antihypertensives

1.8.6.

Treat women with severe hypertension who are in critical care during pregnancy or after birth immediately with 1 of the following:

• labetalol (oral or intravenous)
• oral nifedipine^[3]
• intravenous hydralazine. [2010, amended 2019]

1.8.7.

In women with severe hypertension who are in critical care, monitor their response to treatment:

• to ensure that their blood pressure falls
• to identify adverse effects for both the woman and the baby
• to modify treatment according to response. [2010]

1.8.8.

Consider using up to 500 ml crystalloid fluid before or at the same time as the first dose of intravenous hydralazine in the antenatal period. [2010]

Corticosteroids for fetal lung maturation

1.8.9.

If early birth is considered likely within 7 days in women with pre-eclampsia, offer a course of antenatal corticosteroids in line with the NICE guideline on preterm labour and birth. [2010, amended 2019]

Corticosteroids to manage HELLP syndrome

1.8.10.

Do not use dexamethasone or betamethasone for the treatment of HELLP syndrome. [2010]

Fluid balance and volume expansion

1.8.11.

Do not use volume expansion in women with severe pre-eclampsia unless hydralazine is the antenatal antihypertensive. [2010]

1.8.12.

In women with severe pre-eclampsia, limit maintenance fluids to 80 ml/hour unless there are other ongoing fluid losses (for example, haemorrhage). [2010]

Caesarean section versus induction of labour

1.8.13.

Choose mode of birth for women with severe hypertension, severe pre-eclampsia or eclampsia according to the clinical circumstances and the woman’s preference. [2010]

Referral to critical care

1.8.14.

Refer women with severe hypertension or severe pre-eclampsia to the appropriate critical care setting using the criteria in table 4. [2010]

Table 4

Clinical criteria for choice of critical care level.

Risk of recurrence of hypertensive disorders of pregnancy

1.10.1.

Advise women with hypertensive disorders of pregnancy that the overall risk of recurrence in future pregnancies is approximately 1 in 5 (see table 5). [2019]

Table 5

Likelihood of recurrence of hypertensive disorders of pregnancy.

Long-term risk of cardiovascular disease

1.10.2.

Advise women who have had a hypertensive disorder of pregnancy that this is associated with an increased risk of hypertension and cardiovascular disease in later life (see table 6). [2019]

Table 6

Cardiovascular risk in women who have had a hypertensive disorder of pregnancy.

1.10.3.

Advise women who have had a hypertensive disorder of pregnancy to discuss how to reduce their risk of cardiovascular disease, including hypertensive disorders, with their GP or specialist. This may include:

• avoiding smoking, as recommended in the NICE guideline on stop smoking interventions and services
• maintaining a healthy lifestyle, as recommended in the NICE guideline on cardiovascular disease
• maintaining a healthy weight, as recommended in the NICE guideline on obesity.
• [2019]

1.10.4.

In women who have had pre-eclampsia or hypertension with early birth before 34 weeks, consider pre-pregnancy counselling to discuss possible risks of recurrent hypertensive disorders of pregnancy, and how to lower them for any future pregnancies. [2019]

Body mass index and recurrence of hypertensive disorders of pregnancy

1.10.5.

Advise women who have had pre-eclampsia to achieve and keep a BMI within the healthy range before their next pregnancy (18.5–24.9 kg/m²). See also the NICE guideline on obesity: identification, assessment and management. [2010, amended 2019]

Inter-pregnancy interval and recurrence of hypertensive disorders of pregnancy

1.10.6.

Advise women who have had pre-eclampsia that the likelihood of recurrence increases with an inter-pregnancy interval greater than 10 years. [2010, amended 2019]

Long-term risk of end-stage kidney disease

1.10.7.

Tell women with a history of pre-eclampsia who have no proteinuria and no hypertension at the postnatal review (6–8 weeks after the birth) that although the relative risk of end-stage kidney disease is increased, the absolute risk is low and no further follow-up is necessary. [2010]

Thrombophilia and the risk of pre-eclampsia

1.10.8.

Do not routinely perform screening for thrombophilia in women who have had pre-eclampsia. [2010]

Chronic hypertension

Hypertension that is present at the booking visit, or before 20 weeks, or if the woman is already taking antihypertensive medication when referred to maternity services. It can be primary or secondary in aetiology.

Eclampsia

A convulsive condition associated with pre-eclampsia.

Gestational hypertension

New hypertension presenting after 20 weeks of pregnancy without significant proteinuria.

HELLP syndrome

Haemolysis, elevated liver enzymes and low platelet count.

Hypertension

Blood pressure of 140 mmHg systolic or higher, or 90 mmHg diastolic or higher. [2019]

Multi-fetal pregnancy

A pregnancy with more than 1 baby (such as twins, triplets).

Pre-eclampsia

New onset of hypertension (over 140 mmHg systolic or over 90 mmHg diastolic) after 20 weeks of pregnancy and the coexistence of 1 or more of the following new-onset conditions:

• proteinuria (urine protein:creatinine ratio of 30 mg/mmol or more or albumin:creatinine ratio of 8 mg/mmol or more, or at least 1 g/litre [2+] on dipstick testing) or
• other maternal organ dysfunction:

  -

  renal insufficiency (creatinine 90 micromol/litre or more, 1.02 mg/100 ml or more)

  -

  liver involvement (elevated transaminases [alanine aminotransferase or aspartate

  -

  aminotransferase over 40 IU/litre] with or without right upper quadrant or epigastric abdominal pain)

  -

  neurological complications such as eclampsia, altered mental status, blindness, stroke, clonus, severe headaches or persistent visual scotomata

  -

  haematological complications such as thrombocytopenia (platelet count below 150,000/microlitre), disseminated intravascular coagulation or haemolysis

• uteroplacental dysfunction such as fetal growth restriction, abnormal umbilical artery doppler waveform analysis, or stillbirth.

Severe hypertension

Blood pressure over 160 mmHg systolic or over 110 mmHg diastolic.

Severe pre-eclampsia

Pre-eclampsia with severe hypertension that does not respond to treatment or is associated with ongoing or recurring severe headaches, visual scotomata, nausea or vomiting, epigastric pain, oliguria and severe hypertension, as well as progressive deterioration in laboratory blood tests such as rising creatinine or liver transaminases or falling platelet count, or failure of fetal growth or abnormal doppler findings.

1. Management of chronic hypertension in pregnancy

In women who need treatment for chronic hypertension in pregnancy, what is the effectiveness and safety of antihypertensive agents (compared in head-to-head trials) in improving maternal and perinatal outcomes? [2019]

To find out why the committee made the research recommendation on pre-eclampsia, see rationale and impact.

2. Management of hypertension in pregnancy

In women who need treatment for hypertension in pregnancy, what are the adverse neonatal outcomes associated with maternal use of beta blockers (or mixed alpha-beta blockers)? [2019]

To find out why the committee made these research recommendations on chronic hypertension, see rationale and impact.

3. Management of pre-eclampsia

In which women with pre-eclampsia is inpatient management associated with better outcomes for women and babies? [2019]

To find out why the committee made the research recommendation on pre-eclampsia, see rationale and impact.

4. Antihypertensive treatment during the postnatal period

In women who need treatment for high blood pressure after birth, what is the effectiveness and safety (including in breastfeeding women) of antihypertensive agents in achieving adequate blood pressure control? [2019]

To find out why the committee made the research recommendation on antihypertensive treatment during breastfeeding, see rationale and impact.

5. Fetal monitoring

In women with hypertensive disorders of pregnancy, what is the optimal fetal monitoring strategy to detect small for gestational age infants? [2019]

To find out why the committee made the research recommendation on fetal monitoring, see rationale and impact.

6. Advice and follow-up at transfer to community care

In women who have had hypertension during pregnancy, what interventions reduce the risk of a) recurrent hypertensive disorders of pregnancy, and b) subsequent cardiovascular disease? [2019]

To find out why the committee made the research recommendation on follow-up after hypertensive disorders of pregnancy, see rationale and impact.

Haematological and biochemical monitoring in women with gestational hypertension

What is the role of assessing haematological or biochemical parameters at diagnosis of gestational hypertension and during surveillance of gestational hypertension? [2010]

Why the committee made the recommendations

The committee were aware that there is often over-reliance on a proteinuria result in the diagnosis of pre-eclampsia, and agreed that healthcare professionals should use the results of a full clinical review, including severity of hypertension and other signs and symptoms, before making a diagnosis of pre-eclampsia.

The committee amended the recommendation on automated dipstick tests from the 2010 guideline to emphasise that this should be used as a screening tool for proteinuria. The committee highlighted the importance of using automated dipstick analysis in secondary care rather than visual analysis, which they were aware from their experience has a higher error rate.

Protein:creatinine ratio (PCR) and albumin:creatinine ratio (ACR) were both shown to have high specificity and high sensitivity at the chosen thresholds (30 mg/mmol and 8 mg/mmol respectively), and therefore either could be used depending on local availability. The committee agreed that using both tests together did not have any additional diagnostic benefit.

There was some evidence that using the first morning urine void in assessment of proteinuria can lead to lower diagnostic accuracy, and so the committee recommended against using this.

As PCR and ACR show very high diagnostic accuracy, they should be used in place of 24-hour urine collection, which is awkward for women and could delay identification of proteinuria. However, there are rare occasions when it might be more appropriate to use 24-hour collection (for example, women with renal complications), and so the committee agreed it should not be ruled out entirely.

There was good evidence that a PCR of 30 mg/mmol had good diagnostic accuracy, showing high sensitivity and specificity and should be used as the threshold for significant proteinuria. However, the committee recommended retesting for results above 30 mg/mmol if there is still diagnostic uncertainty (for example, the woman has no other clinical signs or symptoms of pre-eclampsia) because there is large variation in protein excretion during the day and from day to day. The committee agreed that this would prevent women being diagnosed with pre-eclampsia on the basis of a single raised PCR result.

Evidence from a single study showed high sensitivity and specificity for an ACR result of 8 mg/ mmol to diagnose proteinuria. However, the committee were also aware of further results from a large, UK-based study, which provided further evidence for the efficacy of a threshold of 8 mg/ mmol in the diagnosis of severe pre-eclampsia. The committee were aware that this threshold is different to that used for detection of microalbuminuria in the non-pregnant population. However, they agreed that, on the basis of the evidence reviewed, it was appropriate to use a threshold of 8 mg/mmol for pregnant women.

As with PCR, the committee were aware that women are sometimes diagnosed with pre-eclampsia on the basis of a single raised ACR, and that this may lead to over-diagnosis. Therefore they made a recommendation to consider repeating the ACR measurement if there was ongoing clinical uncertainty about the diagnosis.

No evidence was reviewed that examined the timing of repeat testing for either ACR or PCR, and so no recommendations could be made regarding this.

How the recommendations might affect practice

The recommendation to take account of other clinical features when assessing women for suspected pre-eclampsia might lead to an increased need for follow-up and surveillance. However, this will also reduce the chance that a diagnosis of pre-eclampsia is missed by raising awareness of the multi-system nature of the disease, and so could reduce the number of women who go on to develop complications from undiagnosed pre-eclampsia.

Not all secondary care units currently use automated dipstick analysis to screen for proteinuria, so the recommendations might increase the need for automated reagent-strip reading devices. However, the accuracy and reliability of screening will be improved, reducing the need for further investigations for some women and correctly identifying more women who need further testing or investigations.

Moving from 24-hour urine collection to spot urine ACR or PCR will save time, with potential for faster diagnosis, and a reduction in inaccuracies because of incomplete samples. It is also likely to improve quality of life, as the process of completing a 24-hour urine collection is time-consuming and awkward.

A PCR of 30 mg/mmol is already used routinely as a diagnostic threshold and therefore should not change practice. Currently units may use different ACR levels for diagnosis and so the recommendation to use 8 mg/mmol will standardise practice.

Recommendations have been made for the use of either ACR or PCR allowing local decisions to use whichever test is available, so this should not affect practice.

Repeating the PCR or ACR test may incur a small additional cost. However, this should reduce the false positive rate, and mean some women will avoid unnecessary follow-up or intensive monitoring (such as hospital admission) if their proteinuria resolves and is shown to be transient.

Full details of the evidence and the committee’s discussion are in evidence review G: assessment proteinuria.

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Why the committee made the recommendations

The committee agreed that pregnant woman with chronic hypertension should be offered lifestyle advice similar to other adults with hypertension, and in line with the NICE guideline on hypertension in adults.

There was very little evidence available on treatment initiation thresholds for chronic hypertension in pregnancy, so the committee based their recommendations on the values specified in the recent Control of Hypertension in Pregnancy Study (CHIPS) and the NICE guideline on hypertension in adults. There was evidence for target blood pressure levels from the large CHIPS trial, so the committee made recommendations based on this.

There was some very limited evidence of both benefits and harms for different antihypertensive medicines. However, there was not enough evidence to recommend one treatment over another. As labetalol, nifedipine and methyldopa had been recommended in the previous guideline (for gestational hypertension and pre-eclampsia), and these medicines had been used for many years in pregnancy, the committee agreed they should be preferred treatment options for chronic hypertension in pregnancy. Labetalol is specifically licensed for use in pregnancy and so is suggested as the first-line option, with nifedipine as the next alternative, and methyldopa as the third option (as it may lead to more side effects and be the least effective option of the 3).

There was some very limited evidence for the benefits of aspirin in reducing preterm births and neonatal unit admissions, so the committee retained the recommendation on aspirin from the previous guideline, but incorporated it into the section on the treatment of chronic hypertension in pregnancy. The committee noted that the studies used different doses of aspirin (ranging from 50–150 mg daily), and that common practice in the UK was to offer 75–150 mg, therefore this dose range was recommended.

The committee were aware of the link between chronic hypertension and both pre-existing and gestational diabetes, therefore they made an overarching recommendation at the beginning of the guideline to cross-refer to the existing NICE guideline on diabetes in pregnancy.

The committee made a new recommendation referring to the NICE diagnostics guidance on placental growth factor (PIGF) testing as this may be applicable to women with chronic hypertension.

As there is currently a lack of evidence on the difference in outcomes between different antihypertensive medications, and concerns about possible adverse neonatal events from beta blockers, the committee made research recommendations on these topics.

How the recommendations might affect practice

Based on these recommendations, a clear blood pressure target should now be set for women with chronic hypertension in pregnancy who need antihypertensive treatment to improve consistency of treatment targets.

Starting treatment for hypertension and offering aspirin to women with chronic hypertension who are pregnant are standard care, so these recommendations are not expected to change practice significantly.

Full details of the evidence and the committee’s discussion are in evidence review A: interventions for chronic hypertension.

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Why the committee made the recommendations

The committee updated the table from the previous guideline on the management of pregnancy with gestational hypertension. There was very little evidence available on treatment initiation thresholds for gestational hypertension in pregnancy, so the committee made recommendations using the values specified in the recent Control of Hypertension in Pregnancy Study (CHIPS). There was evidence for target blood pressure levels from the large CHIPS trial, so the committee made recommendations based on this. The committee made a new recommendation referring to the NICE diagnostics guidance on placental growth factor (PIGF) testing as this is applicable to women with gestational hypertension.

The committee were aware of the link between gestational hypertension and both pre-existing and gestational diabetes, therefore they made an overarching recommendation at the beginning of the guideline to cross-refer to the existing NICE guideline on diabetes in pregnancy.

There was no evidence on fetal monitoring in gestational hypertension, so the committee made a research recommendation.

How the recommendations might affect practice

The recommendations reflect current clinical practice in many units, but may help standardise practice across the NHS for units that currently use other blood pressure targets.

Full details of the evidence and the committee’s discussion are in evidence review B: monitoring gestational hypertension.

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Why the committee made the recommendations

The committee agreed, based on their clinical expertise, that women with pre-eclampsia should have a full clinical assessment at every antenatal appointment and should be admitted to hospital if there are any concerns about the wellbeing of the woman or her baby. The committee agreed that this would include (but was not limited to) reasons such as severe hypertension or other features of pre-eclampsia indicating increased risk of adverse outcomes.

There was some evidence that the fullPIERS and PREP-S models can help identify women at different risks of adverse outcomes because of pre-eclampsia. There was more extensive validation of the fullPIERS model, and the validation studies were conducted in populations from a range of healthcare settings. The PREP-S model had been developed using a UK population, and validated using data from similar multinational settings. It was noted that further validation of PREP-S was unlikely to be conducted, because of the cost of conducting these studies. The committee therefore agreed that both models could be considered as options, in addition to a full clinical assessment, to help guide decisions relating to interventions and place of care.

The tools predict adverse outcomes in women, but are not designed to predict outcomes for babies. The committee agreed it was important to highlight this.

How the recommendations might affect practice

The use of a full clinical assessment and validated models to predict risk may improve consistency in current practice with regard to admission to hospital for women with pre-eclampsia. Some centres offer admission to all women with pre-eclampsia, whereas others only offer it to a small proportion of women. The guidance might increase the number of women who are admitted to hospital in some centres if admission is not currently routine, but might decrease admission in other centres, thus standardising practice.

Full details of the evidence and the committee’s discussion are in evidence review C: prediction of complications in pre-eclampsia.

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Why the committee made the recommendations

The committee updated the table from the previous guideline on the management of pregnancy with pre-eclampsia. There was limited evidence on the best place of treatment for women with pre-eclampsia. Because of this, the committee made recommendations based on other evidence they reviewed (see evidence review C), which showed that women should be admitted if there were concerns for the wellbeing of the woman or her baby, or a high risk of complications of pre-eclampsia predicted using the fullPIERS or PREP-S model. (See the section of the guideline on assessing pre-eclampsia and evidence review C for more details on the use of the fullPIERS and PREP-S models.)

There was no evidence on treatment initiation thresholds or target blood pressure levels for pre-eclampsia, so the committee based their recommendations on the NICE guideline on hypertension in adults and the values specified in the Control of Hypertension In Pregnancy Study (CHIPS; see evidence review A), which included women with chronic or gestational hypertension.

There was some very limited evidence of both benefits and harms for different pharmacological interventions. However, as there was not enough evidence to recommend one treatment over another, the committee adopted the choices from the previous guideline and recommended choosing a treatment based on previous treatments, side-effect profiles and the woman’s preferences. Labetalol is specifically licensed for use in pregnancy and so is suggested as the first-line option, with nifedipine as the next alternative, and methyldopa as the third option (as it may lead to more side effects and be the least effective option of the 3).

There was limited evidence on the benefits and harms of planned early birth compared with expectant management of pregnancy in women with pre-eclampsia, so the committee recommended that decisions about timing of birth should be based on whether the woman and baby are at risk of adverse outcomes if pregnancy is prolonged. These recommendations were based on those from the previous guideline, and expanded based on international guidelines, which were used by the committee in their clinical practice. Based on the data from HYPITAT-II study, the committee also agreed that pregnancies in women with pre-eclampsia could be managed with continued surveillance to 37 weeks, unless there were specific concerns or indications to offer a planned early birth before then.

There was limited evidence to guide the best place of care for women with pre-eclampsia and their babies, so the committee made a research recommendation.

How the recommendations might affect practice

The recommendations are in line with current best clinical practice, so are unlikely to cause a significant change in practice.

Currently, some units admit all women with pre-eclampsia routinely, some only admit women who they believe to be at a high risk of complications, and some admit very few. Standardising practice could therefore increase or reduce the number of women who will be admitted, depending on a unit’s current practice, but is likely to reduce unwanted variance between units.

Full details of the evidence and the committee’s discussion are in evidence review D: interventions for pre-eclampsia.

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Why the committee made the recommendations

There was very little evidence on the efficacy and safety of antihypertensive agents in postnatal women, so the committee made recommendations based on the NICE guideline on hypertension in adults, with adaptations based on the potential effects of medicines on the baby. The committee therefore recommended the use of an angiotensin converting enzyme (ACE) inhibitor as first-line treatment, except in women of African or Caribbean family origin, in whom a calcium-channel blocker would be used first line. The choice of second-line medicine was modified from the NICE guideline on hypertension in adults as angiotensin receptor blockers, thiazide and thiazide-like diuretics are not recommended during breastfeeding. Therefore the committee agreed that beta-blockers should be used as the second-line antihypertensive agent. The committee also agreed that the medicines with once-daily administration should be used wherever possible and for this reason the committee recommended enalapril in preference to captopril (which is taken 3 times daily) and atenolol as an alternative to labetalol (which is taken 2 to 4 times daily).

Based on their experience, the committee made recommendations on advice for women who wish to breastfeed while taking antihypertensives, and on the monitoring of babies whose mothers are taking antihypertensives.

As there was very little evidence on the effectiveness and safety of antihypertensives for postnatal use, the committee revised the research recommendation made in the 2010 guideline.

How the recommendations might affect practice

There is currently wide variation in practice over use of antihypertensive treatment in the postnatal period, and these recommendations may reduce variation in practice. The recommendations could lead to an increase in the use of atenolol instead of labetalol in the postnatal period.

Full details of the evidence and the committee’s discussion are in evidence review E: postnatal management of hypertension.

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Why the committee made the recommendations

Long-term follow-up studies of women who have experienced hypertensive disorders during pregnancy showed an increased risk of long-term cardiovascular disease and a higher prevalence of hypertensive disorders in subsequent pregnancies compared with women unaffected by hypertensive disorders.

There was no evidence on which interventions could reduce the risk of recurrence of hypertensive disorders of pregnancy or future cardiovascular disease, so the committee made a research recommendation.

How the recommendations might affect practice

Providing guidance and advice to women on future risks and signposting appropriate care and lifestyle advice may be an additional activity for some healthcare professionals, compared with current practice.

Full details of the evidence and the committee’s discussion are in evidence review F: advice at discharge.

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