[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 To find out why the committee made the research recommendation on follow-up after hypertensive disorders of pregnancy, see rationale and impact. Other recommendations for research (from 2010 guideline) 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] Rationale and impact These sections briefly explain why the committee made the recommendations and how they might affect practice. They link to details of the evidence and a full description of the committee's discussion. Assessment of proteinuria 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 of proteinuria. Return to recommendations Treatment of chronic hypertension 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. Return to recommendations Monitoring and treatment of gestational hypertension 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 (PlGF) 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. Return to recommendations Assessment of women with pre-eclampsia 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. Return to recommendations Monitoring and treatment of pre-eclampsia and timing of birth 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. Return to recommendations Antihypertensive treatment during the postnatal period, including during breastfeeding 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. Return to recommendations Risk of recurrence of hypertensive disorders of pregnancy and long-term cardiovascular disease 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. Return to recommendations Context Hypertensive disorders during pregnancy affect around 8% to 10% of all pregnant women and can be associated with substantial complications for the woman and the baby. Women can have hypertension before pregnancy or it can be diagnosed in the first 20 weeks (known as chronic hypertension), new onset of hypertension occurring in the second half of pregnancy (gestational hypertension) or new hypertension with features of multi-organ involvement (pre-eclampsia). Although the proportion of women with pregnancy hypertensive disorders overall appears to have stayed reasonably stable, maternal mortality from hypertensive causes has fallen dramatically: less than 1 woman in every million who gives birth now dies from pre- eclampsia. There is consensus that introduction of the 2010 NICE evidence-based guidelines, together with the findings from the confidential enquiry into maternal deaths, has made a pivotal contribution to this fall in maternal mortality. However, hypertension in pregnancy continues to cause substantial maternal morbidity, stillbirths and neonatal deaths, and perinatal morbidity. Women with hypertension in pregnancy are also at increased risk of cardiovascular disease later in life. Variations in care contribute to inequity in adverse outcomes. Adoption and implementation of evidence-based national guidelines have a central role in reducing this variance and improving care and outcomes across the maternity service. Research that has been done since publication of the previous guideline has addressed areas of uncertainty and highlighted where the recommendations can be updated. A surveillance report from 2017 identified new studies in the following areas: management of pregnancy with chronic hypertension management of pregnancy with gestational hypertension management of pregnancy with pre-eclampsia breastfeeding advice and follow-up care at transfer to community care. The scope of this update was limited to these sections; it did not include other areas being looked at by other groups (for example, screening strategies for pre-eclampsia, which is being evaluated by the UK National Screening Committee), and did not look into alternative approaches to categorisation of hypertension in pregnancy (for example, looking at treatment for all types of pregnancy hypertension together, rather than within the subdivisions of chronic hypertension, gestational hypertension and pre-eclampsia). This update has also clarified the basis for the current definition of pre-eclampsia, in order to better align with the stated aims of the 2010 guideline to be consistent with those agreed by the International Society for the Study of Hypertension in Pregnancy (ISSHP). The aim of the 2019 guideline is to present updated evidence-based recommendations, relevant to practising clinicians, while identifying outstanding areas of uncertainty that need further research. There is a strong argument for uptake of these new guidelines into clinical practice, in order to minimise unnecessary variance and provide optimal care for women and their babies. In doing this, low rates of maternal mortality should be maintained, and progress on reduction of maternal morbidity and perinatal morbidity and mortality can be pursued. Finding more information and committee details To find NICE guidance on related topics, including guidance in development, see the NICE topic page hypertension. For full details of the evidence and the guideline committee's discussions, see the evidence reviews. You can also find information about how the guideline was developed, including details of the committee. NICE has produced tools and resources to help you put this guideline into practice. For general help and advice on putting NICE guidelines into practice, see resources to help you put NICE guidance into practice. Update information April 2023: In recommendations 1.3.12 and 1.4.4, we updated the information about when placental growth factor (PLGF)-based testing for pre-eclampsia should be carried out. This brings it in line with our diagnostics guidance on PLGF-based testing to help diagnose suspected preterm pre-eclampsia. June 2019: We have reviewed the evidence on the assessment of proteinuria and the treatment of women with chronic and gestational hypertension and pre-eclampsia, breastfeeding and advice on discharge. These recommendations are marked [2019]. We have also made some changes without an evidence review: Combined, updated and clarified advice throughout to make it simpler to follow. Updated advice on pre-eclampsia in line with the NICE guidelines on antenatal care and pre-term labour and birth. Amended dose information for aspirin use in pre-eclampsia in line with current national guidance. Updated advice on rest, exercise and work for women with pre-eclampsia in line with the NICE guideline on antenatal care. Expanded the advice on the risks of angiotensin-converting enzyme (ACE) inhibitors to treat hypertension in pregnancy. Expanded and amended the advice on chlorothiazide to thiazide and thiazide-like diuretics, because chlorothiazide is no longer widely used. Updated terminology used for various aspects of treatment in line with current practice. Updated the advice on when to offer planned early birth and action to take beforehand. Updated the advice on continuing antihypertensive treatment after birth, including treatment with methyldopa. Added cross references where suitable to NICE guidance on breastfeeding. Updated guidance if necessary to be more specific on which healthcare professionals are responsible for undertaking reviews and checks. Updated scan and test times for women with chronic hypertension in pregnancy, and why scans and tests may be needed. Updated advice about creating care plans and who should be involved. Updated advice on anti-convulsants. Updated advice on angiotensin-receptor blockers during breastfeeding. Updated definitions and terms used to reflect current clinical practice. These recommendations are marked [2010, amended 2019]. Recommendations marked [2010] last had an evidence review in 2010. In some cases, minor changes have been made to the wording to bring the language and style up to date, without changing the meaning. Minor changes since publication October 2022: We added text to indicate that pulse oximetry may be less reliable in people with dark skin. We also added a link to the NHS patient safety alert on the risk of harm from inappropriate placement of pulse oximeter probes. See recommendation 1.5.7. August 2022: We corrected the term 'first pregnancy' to 'nulliparity' in recommendation 1.1.3. Accreditation