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).
Term |
Definition used in the guideline |
FETAL COMPROMISE |
Reduced fetal movements, small for gestational age infant |
HYPERTENSION |
A diastolic blood pressure of 90 mmHg or more |
NEW HYPERTENSION |
Hypertension at or after 20 weeks gestation in a woman with a diastolic blood pressure of less than 90mmHg before 20 weeks |
PRE-EXISTING HYPERTENSION |
A diastolic blood pressure pre-pregnancy or at booking (before 20 weeks) of 90mmHg or more |
NEW PROTEINURIA |
The presence of proteinuria as shown by 1+ (0.3g/l) or more on proteinuria dipstick testing, a protein/creatinine ratio of 30mg/mmol or more on a random sample or a urine protein excretion of 300mg or more per 24 hours |
SIGNIFICANT PROTEINURIA |
Urine protein excretion >300mg per 24 hr |
PRE-ECLAMPSIA |
New hypertension and significant proteinuria at or after 20 weeks of pregnancy, confirmed if it resolves after delivery |
SUPERIMPOSED PRE-ECLAMPSIA |
The development of features of pre-eclampsia in the context of pre-existing hypertension, pre-existing proteinuria or both |
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
FACTOR |
PRECOG Grade |
First pregnancy |
B |
Multiparous with
- Pre-eclampsia in any previous pregnancy
- Ten years or more since last baby
|
B
B
|
Age 40 years or more |
B |
Body Mass Index of 35 or more |
B |
Family history of pre-eclampsia (in mother or sister) |
B |
Booking diastolic blood pressure of 80 mmHg or more |
B |
Booking proteinuria (of >1+ on more than one occasion or quantified at >0.3 g/24 hr) |
C |
Multiple pregnancy |
B |
Certain underlying medical conditions:
- Pre-existing hypertension
- Pre-existing renal disease
- Pre-existing diabetes
- Antiphospholipid antibodies
|
B |
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
FACTOR |
PRECOG Grade |
Multiple pregnancy |
D |
Underlying medical conditions:
- Pre-existing hypertension or booking diastolic blood pressure (BP) >90 mmHg
- Pre-existing renal disease or booking proteinuria (>1+ on more than one occasion or quantified at >0.3 g/24 hour)
- Pre-existing diabetes
- Antiphospholipid antibodies
|
D
D
D
D
|
Pre-eclampsia in any previous pregnancy |
D |
Any two other pre-disposing factors from Recommendation 1 (i.e., first pregnancy, age 40 years or more, body mass index >35, family history, booking diastolic BP >80 mmHg <90 mmHg) |
GPP* |
*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
Frequency Level |
Women who Qualify** |
Frequency interval |
24 to 32 weeks' gestation |
32 weeks' gestation to delivery |
LEVEL 1 |
None of the predisposing factors listed in Recommendation 1 |
As per local protocols/NICE Antenatal guideline for low risk multiparous women |
As per local protocols/NICE Antenatal Guideline for low risk multiparous women |
LEVEL 2 |
One predisposing factor listed in Recommendation 1. No factor that requires referral in early pregnancy (Recommendation 2). |
Minimum standard no more than 3-week interval between assessments, adjusted to individual needs and any changes during pregnancy*** |
Minimum standard no more than 2-week interval between assessments, adjusted to individual's needs and any changes during pregnancy*** |
*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
Signs and Significant Symptoms |
PRECOG Grade |
|
B |
- New and/or significant proteinuria
|
B |
- Maternal symptoms of headache and/or visual disturbance
|
C |
- Epigastric pain and/or vomiting
|
C |
- Reduced fetal movements, small for gestational age infant
|
B |
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
Description |
Definition |
Action by midwife/GP |
PRECOG Grade |
New hypertension without proteinuria after 20 weeks |
Diastolic BP >90 and <100 mmHg |
Refer for hospital step-up assessment within 48 hours |
C |
Diastolic BP >90 and <100 mmHg with significant symptoms* |
Refer for same day hospital step-up assessment |
C |
Systolic BP >160 mmHg |
Refer for same day hospital step-up assessment |
C |
Diastolic BP >100 mmHg |
Refer for same day hospital step-up assessment |
C |
New hypertension and proteinuria after 20 weeks |
Diastolic BP >90 mmHg and new proteinuria >1+ on dipstick |
Refer for same day hospital step-up assessment |
A |
Diastolic BP >110 mmHg and new proteinuria >1+ on dipstick |
Arrange immediate admission |
A |
Systolic BP >170 mmHg and new proteinuria >1+ on dipstick |
Arrange immediate admission |
A |
Diastolic BP >90 mmHg and new proteinuria >1+ on dipstick and significant symptoms* |
Arrange immediate admission |
A |
New proteinuria without hypertension after 20 weeks |
1+ on dipstick |
Repeat pre-eclampsia assessment in community within 1 week |
C |
2+ or more on dipstick |
Refer for hospital step-up assessment within 48 hours |
C |
>1+ on dipstick with significant symptoms* |
Refer for same day hospital step-up assessment |
C |
Maternal symptoms or fetal signs and symptoms without new hypertension or proteinuria |
Headache and or visual disturbances with diastolic blood pressure less than 90 mmHg and a trace or no protein |
Follow local protocols for investigation. Consider reducing interval before next PRECOG assessment |
C |
Epigastric pain with diastolic blood pressure less than 90 mmHg and a trace or no protein |
Refer for same day hospital step-up assessment |
C |
Reduced movements or small for gestational age infant with diastolic blood pressure less than 90 mmHg and a trace or no protein |
Follow local protocols for investigation of fetal compromise. Consider reducing interval before next full pre-eclampsia assessment |
C |
*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