This is the current release of the guideline.

Pre-eclampsia

Diagnosis
Evaluation
Risk Assessment
Screening

Family Practice
Internal Medicine
Obstetrics and Gynecology

Advanced Practice Nurses
Patients
Physician Assistants
Physicians
Public Health Departments

• To provide recommendation for the antenatal care of pregnancies where pre-eclampsia is more likely to develop
• To outline the appropriate response to indications of the onset of pre-eclampsia for all pregnant women
• To provide a framework for antenatal care in the community in which a pregnant woman with pre-eclampsia is referred for specialist care at the appropriate time for her and her baby

Note: This guideline does not cover hospital obstetric day unit or in-patient care, post-natal onset, or post-natal management of pre-eclampsia

All pregnant women

1. Identification of factors that predispose a pregnancy to pre-eclampsia
2. Referral of women with predisposing factors for early investigation
3. Community monitoring after 20 weeks for indications of pre-eclampsia according to risk level
4. Evaluation for 5 significant signs and symptoms of pre-eclampsia:
   • New hypertension
   • New and/or significant proteinuria
   • Maternal symptoms of headache and/or visual disturbance
   • Epigastric pain and/or vomiting
   • Reduced fetal movements, small for gestational age infant
5. Continued monitoring for pre-eclampsia using:
   • Diastolic blood pressure (BP)
   • Systolic blood pressure
   • Urine dipstick (measurement of proteinuria)
6. Assessment of fetal compromise
7. Referral for hospital step-up assessment or immediate admission

• Sensitivity and specificity of diagnostic tests
• Predictive value of diagnostic tests
• Maternal and fetal morbidity and mortality
• Birth weight
• Risk of pre-eclampsia

Hand-searches of Published Literature (Primary Sources)
Hand-searches of Published Literature (Secondary Sources)
Searches of Electronic Databases
Searches of Unpublished Data

The evidence was identified from published studies and from unpublished Cochrane Reviews. In addition, the guideline developers identified a meta-analysis of risk factors for pre-eclampsia. Relevant evidence-based guidelines were also considered (and otherwise unpublished data contained within them). No studies were excluded solely on the year in which they were published, as valuable data on the natural course of the condition can be obtained from earlier studies. The remit of the guideline was agreed by the PRECOG Development Group and the MEDLINE and EMBASE electronic databases were searched using key words related to sections within the guideline. Experts in the field were also consulted.

103

Weighting According to a Rating Scheme (Scheme Given)

Grading of Evidence

1a*: Evidence obtained from meta-analysis of randomised controlled trials

1b: Evidence obtained from at least one randomised controlled trial

IIa: Evidence obtained from at least one well-designed controlled study without randomisation. Includes cohort studies

IIb: Evidence obtained from at least one other type of well-designed quasi-experimental study. Includes case control studies

III: Evidence obtained from well-designed non-experimental descriptive studies, such as comparative studies, correlation studies, and case studies

IV: Evidence obtained from expert committee reports or opinions and/or clinical experience of respected authorities

*The highest level of evidence

Review of Published Meta-Analyses
Systematic Review with Evidence Tables

Full papers were obtained of every selected paper. These were reviewed and summarized as shown in the Evidence Tables. The studies were graded independently by two colleagues in the Pre-eclampsia Community Guideline (PRECOG) group using the grading system described in the "Rating Scheme for the Strength of the Evidence" and "Rating Scheme for the Strength of the Recommendations" fields.

Expert Consensus

The guideline has been developed by a multi-professional and lay working group (the Pre-eclampsia Community Guideline [PRECOG] development group) representing parties involved in the provision or use of maternity services in the United Kingdom. The group was convened by the national charity Action on Pre-eclampsia (APEC) and has been funded in part through educational grants or grant in kind from Bayer plc and GlaxoSmithKline plc. The group has included obstetricians and obstetric physicians who specialise in pre-eclampsia, representatives from teaching hospitals, district general hospitals and day-care obstetric units, general practitioners, midwives, and a health economist. Among the group were nominated representatives of the Royal College of Midwives, Royal College of General Practitioners, and from two key user groups: the National Childbirth Trust and Action on Pre-eclampsia. Please see page 19 of the original guideline document for names of participants.

The group followed a guideline development process that drew on methodology outlined in the National Health Service (NHS) National Institute for Health and Clinical Excellence (NICE) publication "The Guideline Development Process - Information for National Collaborating Centres and Guideline Development Groups (December 2001)" and the British Medical Journal criteria for guidelines, which is adapted from the US Agency for Health Care Policy and Research.

The PRECOG development group first defined the remit of the guideline, after which a systematic review of the literature was conducted. The recommendations were developed by the group and graded according to the levels of evidence on which they were based. In the guideline the recommendations are explicitly linked to the highest level of evidence available.

The accompanying document "Evidence Used to Develop the PRECOG Guideline" gives more detail of the methodology of the process, and the evidence supporting each recommendation. It includes:

• A description of each relevant study or meta-analysis of studies, from systemic review, which were considered in the development of the recommendation. Each piece of evidence is graded.
• A summary of the evidence, consideration of other guidelines and consensus of the PRECOG development group
• The subsequent recommendation graded according to the highest level of evidence available

At the same time a national survey of maternity units across the UK (Action on Pre-eclampsia, 2002) provided data on the patterns of referral into hospital day units for suspected pre-eclampsia, and assessment procedures and policies. This information was fed into the development group and also used to provide a statement on resource implications.

Grading of Recommendations

Grade A*: Directly based on category I evidence

Grade B: Directly based on category II evidence or extrapolated recommendation from category I evidence

Grade C: Directly based on category III evidence or extrapolated recommendation from category I or II evidence

Grade D: Directly based on category IV evidence or extrapolated recommendation from category I, II or III evidence

Good practice point (GPP): The view of the guideline development group.

Note: The grading of recommendations follows that adopted in the National Institute for Health and Clinical Excellence (NICE) guideline and differs from recent Royal College of Obstetricians and Gynaecologists (RCOG) recommendations: see "Evidence used to develop the Pre-eclampsia Community Guideline (PRECOG) guideline" in the "Availability of Companion Documents" field for further details.

*The highest grade

A formal cost analysis was not performed and published cost analyses were not reviewed.

Clinical Validation-Pilot Testing
External Peer Review
Internal Peer Review

Validation

The guideline validation process has involved:

• Peer review by independent reviewers not involved in the development of the guideline (see page 19 of the original guideline document for names). Their comments and the Pre-eclampsia Community Guideline (PRECOG) group responses are available from the offices of Action on Pre-eclampsia
• Presentation at the following national society conferences: International Society for the Study of Hypertension in Pregnancy 2003 (plenary session), Royal College of Midwives Annual Conference 2004 (poster presentation), British Congress of Obstetrics and Gynaecology 2004 (oral presentation)
• The official review process of the Royal College of Obstetrics and Gynaecology, the Royal College of Midwives, the Royal College of General Practitioners, the National Childbirth Trust. These organizations endorsed the guideline.
• Submission for publication to a peer-review journal (accepted for publication by the British Medical Journal)

Pre-pilot and Extended Pilot

From 2004 the guideline and associated materials and the audit form have been tested for:

• Ease of use
• Issues concerning the integration of the guideline into existing policies and procedures at local level
• Response of pregnant women
• Outcome measures

The grades of recommendations (A-D) and levels of evidence (Ia, Ib, IIa, IIb, III, and IV) are defined at the end of the "Major Recommendations" field.

In addition to evidence-based recommendations, the guideline development group also identifies good practice points (GPP).

Note that there are no uniformly adopted definitions for pregnancy induced hypertension, gestational hypertension or severe pre-eclampsia. The terms are only used in the guideline when referring to a study definition, which is given in parentheses and/or in the Evidence Tables.

Pre-eclampsia Community Guideline (PRECOG) Recommendation 1

Identify the presence of any one of the following factors that predispose a woman in a given pregnancy to pre-eclampsia. [Grade B/C]

Box 1: Factors that can be measured early in pregnancy that increase the likelihood of pre-eclampsia developing in any given pregnancy

PRECOG Recommendation 2

Offer pregnant women with the following predisposing factors for pre-eclampsia referral early in pregnancy for specialist input to their antenatal care plan [Grade D/GPP]. The factors indicate an underlying pathology, concomitant condition, or otherwise high level of obstetric risk related to pre-eclampsia, which would benefit from specialist input: this may be for further specialist investigation, for clarification of risk, or to advise on early intervention or pharmacological treatment.

It is not within the remit of this guideline to prescribe specialist-led care or to exclude general practitioner (GP) or midwife led care. It is recognised that all women benefit from a continuity of care and need midwifery care as part of their individual antenatal care plan, whatever their obstetric risk.

Box 2: Factors for referral in early pregnancy for specialist input to care

*Note that the effect of two pre-disposing factors on the overall likelihood of developing pre-eclampsia has yet not been studied, so there is no evidence. Therefore the recommendation that these women would benefit from specialist input to assess their obstetric risk is the opinion of the pre-eclampsia specialists in the PRECOG group.

PRECOG Recommendation 3a

Offer pregnant women one of two levels of midwife/GP-led community monitoring after 20 weeks* for indications of pre-eclampsia, according to their level of risk of developing pre-eclampsia [Grade B]

Box 3: Frequency of community monitoring after 20 weeks for indications of pre-eclampsia

*By definition pre-eclampsia cannot be diagnosed before 20 weeks' gestation.

**Note that women who have been referred early in pregnancy (See Recommendation 2) do not qualify for level 1 or level 2 or midwife or GP-led PRECOG community monitoring.

***Interval corresponds to NICE Antenatal Guideline for primiparous women.

Recommendation 3b

All pregnant women should be aware that after 20 weeks' gestation pre-eclampsia may develop between antenatal assessments and that it is appropriate for them to self-refer at any time. [Grade B]

Recommendation 4

At every PRECOG assessment the healthcare provider and pregnant women should identify the presence of any one of the five significant signs and symptoms of the onset of pre-eclampsia and act according to Recommendation 5. [Grade B and C]

Box 4: Community monitoring: content

Description of Symptoms [GPP]

As there are limited data from studies, the following are descriptions and comments from the pre-eclampsia specialists in the PRECOG group and the Confidential Enquiries into Maternal Deaths in the United Kingdom (CEMD) [Good Practice Points]:

Headache and Visual Disturbances

• Severe pounding headache, partial loss of visual acuity, bright/flashing visual disturbances. Migraines can continue during pregnancy and any migraine can be excruciating without being life threatening or associated with signs of pre-eclampsia.
• A headache of sufficient severity to seek medical advice (CEMD)

Epigastric Pain

• Epigastric pain, especially if severe or associated with vomiting. The most sinister epigastric pain is described by the sufferer as severe and is associated with definite tenderness to deep epigastric palpation (the woman winces)
• New epigastric pain (CEMD)

Recommendation 5

Box 5: Community monitoring: thresholds for further action

*Epigastric pain, vomiting, headache, visual disturbances, reduced fetal movements, small for gestational age infant

Recommendation 6

Reducing Errors in Blood Pressure Measurement

• Use accurate equipment (mercury sphygmomanometer or validated alternative method). [Grade C]
• Use sitting or semi-reclining position so that the arm to be used is at the level of the heart. [GPP]
• Do not take the blood pressure in the upper arm with the woman on her side as this will give falsely lower readings.[Grade D]
• Use appropriate size of cuff: standard size (13 x 23 cm) for an arm circumference of up to 33 cm, a large size (33 x 15 cm) for an arm circumference between 33 and 41cm) and a thigh cuff (18 x 36cm) for an arm circumference of 41cm or more. There is less error introduced by using too large a cuff than by too small a cuff. [Grade C]
• Deflate the cuff slowly, at a rate of 2 mmHg to 3 mmHg per second, taking at least 30 seconds to complete the whole deflation. [Grade D]
• Use Korotkoff V (disappearance of heart sounds) for measurement of diastolic pressure, as this is subject to less intra-observer and inter-observer variation than Korotkoff IV (muffling of heart sounds) and seems to correlate best with intra-arterial pressure in pregnancy. [Grade A] In the 15% of pregnant women whose diastolic pressure falls to zero before the last sound is heard, then both phase IV and phase V readings should be recorded (e.g., 148/84/0 mmHg). [GPP]
• Measure to the nearest 2 mmHg to avoid digit preference. [Grade D]
• Obtain an estimated systolic pressure by palpation, to avoid auscultatory gap. [Grade D]
• If two readings are necessary, use the average of the readings and not just the lowest reading. This will minimize threshold avoidance (the tendency to repeat a reading until one that is below a known threshold is recorded that requires no action). [GPP]

PRECOG Recommendation 7

Improving Reliability of Proteinuria Estimate Using Dipstick Testing

The performance of a semi-quantitative dipstick is dependent on many variables, including how the dipstick is read (by all comers to a clinic, staff at a routine clinic, trained research observers, or a machine) and the urine concentration of the sample. The performance of quantitative methods of measuring protein is also dependent on a number of factors, such as the adequate collection of a 24 hour sample and the method used to measure protein.

• Reduce false positive results by training the reader of the dipstick to use the correct methodology to read the dipstick tests. Manufacturer's recommendations should be followed. [Grade C]
• Automated dipstick readers reduce reader error [Grade C]
• Do not repeat a test on a second sample, as this does not improve the predictive value of result for significant proteinuria [Grade D]
• Use a 24 hour urine collection to quantify excreted protein. The use of a protein/ creatinine ratio instead of a 24 hour urinary protein requires local confirmation of performance, as the method of measuring proteinuria has been shown to modify the results [Grade C]
• Reduce concentration-related errors by assessing specific gravity or urine creatinine simultaneously with the protein dip result [Grade C]
• When required, confirm a 1+ result from a dipstick test for proteinuria by measuring protein excretion in a 24 hour urine collection [Grade C]

Recommendation 8

Assessment of Fetal Compromise in the Community

There is limited evidence to recommend a particular method of determining fetal growth and well being in the community, with no evidence to support the superiority of one method over another.

Please refer to the companion Evidence Document (see "Availability of Companion Documents" field) for a summary of the National Institute for Health and Clinical Excellence (NICE) Antenatal Guideline recommendations on assessment of fetal size and wellbeing. The Royal College of Obstetricians and Gynaecologists (RCOG) Guideline recommendations, entitled "RCOG Guideline Investigation and Management of the Small for Gestational Age Fetus" covers the method and predictive value of biometric and biophysical tests for diagnosis and management of the fetus. (RCOG, 2002)

Definitions:

Grading of Recommendations

Grade A*: Directly based on category I evidence

Grade B: Directly based on category II evidence or extrapolated recommendation from category I evidence

Grade C: Directly based on category III evidence or extrapolated recommendation from category I or II evidence

Grade D: Directly based on category IV evidence or extrapolated recommendation from category I, II or III evidence

Good practice point (GPP): The view of the guideline development group.

Note: The grading of recommendations follows that adopted in the National Institute for Health and Clinical Excellence (NICE) guideline and differs from recent Royal College of Obstetricians and Gynaecologists (RCOG) recommendations: see "Evidence used to develop the Pre-eclampsia Community Guideline (PRECOG) guideline" in the "Availability of Companion Documents" field for further details.

*The highest grade

Grading of Evidence

1a*: Evidence obtained from meta-analysis of randomised controlled trials

1b: Evidence obtained from at least one randomised controlled trial

IIa: Evidence obtained from at least one well-designed controlled study without randomisation. Includes cohort studies

IIb: Evidence obtained from at least one other type of well-designed quasi-experimental study. Includes case control studies

III: Evidence obtained from well-designed non-experimental descriptive studies, such as comparative studies, correlation studies, and case studies

IV: Evidence obtained from expert committee reports or opinions and/or clinical experience of respected authorities

*The highest level of evidence

None provided

The type of supporting evidence is identified and graded for each recommendation (see "Major Recommendations").

• Appropriate screening and early detection of pre-eclampsia in the community and appropriate referral from community to step-up care
• If the recommendations in this guideline are followed, pregnant women will be alerted to the possibility of developing pre-eclampsia during pregnancy, the symptoms to look out for, and the care they may need.

Subgroup Most Likely to Benefit

As more women in the population with predisposing factors will develop pre-eclampsia -- by definition of relative risk -- early detection and reduction in morbidity will benefit this group more overall.

Not stated

Getting Better
Staying Healthy

Effectiveness
Timeliness

Not applicable: The guideline was not adapted from another source.

2004

Action on Pre-eclampsia - Private Nonprofit Organization

Not stated

PRECOG Development Group

PRECOG Development Group Members: Phil Baker, Obstetrician; Julian Bradley, General Practitioner, RCGP Representative; Janet Bray, Medical Writer; Carol Cooper, General Practitioner; David Davies, Obstetrician; Kirsten Duckitt, Obstetrician; Michael de Swiet, Obstetric Physician; Gillian Fletcher, Representing pregnant women; Mervi Jokinen, Midwife, RCM Representative; Fiona Milne, Guideline Coordinator; Deidre Murphy, Obstetrician; Catherine Nelson-Piercy, Obstetric Physician; Vicki Osgood, Obstetrician; Chris Redman, Obstetric Physician; Steve Robson, Obstetrician; Andrew Shennan, Obstetrician; Angela Tuffnell, Midwife; Sara Twaddle, Health Economist; James Walker, Obstetrician; Jason Waugh, Obstetrician

All members of the group have been invited to report conflicts of interest and none were recorded.

National Childbirth Trust - Medical Specialty Society
Royal College of General Practitioners - Medical Specialty Society
Royal College of Midwives - Medical Specialty Society
Royal College of Obstetricians and Gynaecologists - Medical Specialty Society

This is the current release of the guideline.

This NGC summary was completed by ECRI on May 23, 2005. The information was verified by the guideline developer on June 17, 2005.

This NGC summary is based on the original guideline, which is subject to the guideline developer's copyright restrictions.