Clinical Practice Guidelines Antenatal care - Module I

Clinical assessments

Page last updated: 02 April 2013

Gestational age assessment

NICE recommendations

Pregnant women should be offered an early ultrasound scan between 10 weeks 0 days and 13 weeks 6 days to determine gestational age and to detect multiple pregnancies. This will ensure consistency of gestational age assessment and reduce the incidence of induction of labour for prolonged pregnancy. [not graded]

Crown–rump length measurement should be used to determine gestational age. If the crown–rump length is above 84 mm, the gestational age should be estimated using head circumference. [not graded]

Research questions

1. What is the most accurate method to arrive at an agreed due date (eg last menstrual period [LMP], crownrump length [CRL], biparietal diameter [BPD])? (Informed Recommendation 2)
2. Which women should be offered a dating scan? (Informed Recommendation 2)
3. When is the best time to conduct a dating scan? (Informed Recommendation 2)
4. What is the cost effectiveness of offering women a dating scan? (Cost analysis undertaken)
5. Is it feasible to offer all women a dating scan? (Cost analysis undertaken)
6. What are the other potential benefits of a first trimester scan? (No new evidence found)
7. Who should conduct a dating scan? (No studies identified)
8. What are the potential harms caused by a dating scan? (Limited evidence identified)
9. What are the issues of access to dating scans for rural and remote woman? (No studies identified)
10. What are the issues for some women if unable to get accurate measurements abdominally especially if male sonographer? (No studies identified)
11. Are dating scans done by occasional operator accurate? (No studies identified)
12. What are the risks of induction if dates not accurate? (Beyond scope)
13. Are there risks that placenta praevia is over-diagnosed in early ultrasound scans, and if so, does this contribute to elevated anxiety? (No studies identified)
14. What are the additional considerations for Indigenous Australian women? (Informed narrative)
15. What are the cost implications of a dating scan in remote areas? (Informed narrative)

Search Strategy

Databases searched: Medline; Embase; Psychinfo; Cochrane Database of systematic Reviews; Australasian Medical Index.
Date of searches: March 2009; November 2010
Limits: English language
Publication dates for searches:
1. January 2007 onwards (January 2000 onwards in Australian databases)
2. January 2008–12 November 2010

Review findings

1. 5 level III-2 studies and 1 level IV study
2. No direct evidence to change NICE recommendation
3. 1 level I study and 1 level III-2 study that support ‘early’ ultrasound
4. See Appendix E
5. See Appendix E
6. No new studies identified. Potential benefits include decreased anxiety and decreased induction of labour.
7. No studies identified. Reference made to relevant professional bodies in Australia.
8. No evidence found on harms except for one study which examined potential harm to the fetus caused by exposure to acoustic energy.
9. No studies identified. Narrative informed by Working Group for Aboriginal and Torres Strait Islander Women’s Antenatal Care.
10. No evidence found
11. No evidence found
12. Beyond scope
13. No evidence found
14. Narrative informed by Working Group for Aboriginal and Torres Strait Islander Women’s Antenatal Care
15. Narrative informed by Working Group for Aboriginal and Torres Strait Islander Women’s Antenatal Care
The review identified a systematic review and a number of lower level studies that support the NICE recommendation. Economic analysis was undertaken to assess the cost implications of recommending routine ultrasound in the first trimester (see Appendix E).
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EAC recommendation

2. Provide information and offer pregnant women an ultrasound between 8 weeks 0 days and 13 weeks 6 days to determine gestational age, detect multiple pregnancies and accurately time fetal anomaly screening. Use crown–rump length measurement to determine gestational age. If the crown–rump length is above 84 mm, estimate the gestational age using head circumference.

Evidence supporting recommendation (see Section 7.1.4)

Alexander et al 1995; Crowther et al 1999; Dietz et al 2007; Hoffman et al 2008; Johnsen et al 2006; Koster et al 2008; Martins et al 2008; McLennan & Schluter 2008; Morin 2005; Nguyen 1999; Okonofua 1989; Olesen & Thomsen 2006; Rowlands & Roysten 1993; Salpou et al 2008; Savitz et al 2002; Selbing 1983; Taipale 2001; Verberg et al 2008; Whitworth et al 2010

Grading of evidence — Recommendation 2

Evidence base - B
Consistency - B
Clinical impact - A
Generalisablity - B
Applicability - A
Recommendation - B

Weight and body mass index

NICE recommendations

Maternal weight and height should be measured at the first antenatal appointment, and the woman’s BMI calculated (weight [kg]/height[m]2). [B]
Repeated weighing during pregnancy should be confined to circumstances where clinical management is likely to be influenced. [C]

Research questions

1. How and when should maternal weight, height and BMI be measured in the general maternity population? (Informed Recommendation 3)
2. What information should be provided to women regarding healthy weight in pregnancy ? (Informed Recommendation 4)
3. What dietary advice should be provided to pregnant women (see review on nutritional supplements)
4. What specific risk assessments are required for pregnant women above and below their most healthy weight? (Informed narrative)
5. What are the additional needs of Aboriginal or Torres Strait Islander women ? (Informed narrative)

Search Strategy

Databases searched: Medline; Embase; Informit; Cochrane Database of systematic Reviews; Australasian Medical Index.
Date of search: November 2010
Limits: English language
Publication dates for search: January 2003 – November 2010

Review findings

1. There is evidence from 5 level III-2 studies to support the NICE (2003) recommendation to record height, weight and BMI at the antenatal booking visit and this is advised in other clinical practice guidelines.
2. New evidence regarding the risks associated with a high or low pre-pregnancy BMI has emerged since the NICE (2003) recommendation, including 1 level I, 4 level II, and 7 level III-2 studies. The evidence is also consistent regarding the risk of excessive gestational weight gain for women of normal to high pre-pregnancy BMI, and the risk of poor weight gain for women who have a pre-pregnancy BMI in the underweight category. Recommendations for gestational weight gain are less clear.
3. 2 level I and 4 level II studies were identified that supported the provision of verbal and written information.
4. There is evidence from 7 level III-2 studies and 1 level IV study to support assessment of the associated risks of high pre-pregnancy BMI and enhanced surveillance for small-for-gestational age babies for women with a prepregnancy BMI in the underweight category. This informed the narrative.
5. 1 level III-2 and I level IV study informed the narrative on risks associated with low pre-pregnancy BMI.
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EAC recommendations

3. Measure women’s weight and height at the first antenatal visit and calculate their BMI.
4. Give women advice about appropriate weight gain during pregnancy in relation to their BMI.

Evidence supporting recommendations (see Section 7.2.5)

Recommendation 3 — Bodnar et al 2009; Callaway et al 2006; Chu et al 2007a; Chu et al 2007b; Dawes & Grudzinskas 1991; HAPO 2010; Khashan & Kenny 2009; McDonald et al 2010; Oddy et al 2009; Panaretto et al 2006; Rassmussen et al 2008; Siega-Riz et al 1996; Stothard et al 2009; Thornton et al 2009; Viswanathan et al 2008
Recommendation 4 — Dodd et al 2010; Jeffries et al 2009; Ronnberg et al 2010; Streuling et al 2010

Grading of evidence — Recommendation 3

Evidence base - B
Consistency - B
Clinical impact - B
Generalisablity - B
Applicability - B
Recommendation - B

Grading of evidence —Recommendation 14

Evidence base - A
Consistency - B
Clinical impact - B
Generalisablity - B
Applicability - B
Recommendation - B

Blood pressure

NICE recommendations

At the booking appointment, the following risk factors for pre-eclampsia should be determined:
  • age 40 years or older
  • nulliparity
  • pregnancy interval of more than 10 years
  • family history of pre-eclampsia
  • previous history of pre-eclampsia
  • body mass index 30 kg/mē or above
  • pre-existing vascular disease such as hypertension
  • pre-existing renal disease
  • multiple pregnancy.
Blood pressure measurement and urinalysis for protein should be carried out at each antenatal visit to screen for pre-eclampsia. More frequent blood pressure measurements should be considered for pregnant women who have any of the above risk factors.
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The presence of significant hypertension and/or proteinuria should alert the healthcare professional to the need for increased surveillance.

Hypertension in which there is a single diastolic blood pressure of 110 mmHg or two consecutive readings of 90 mmHg at least 4 hours apart and/or significant proteinuria (1+) should prompt increased surveillance. If the systolic blood pressure is above 160 mmHg on two consecutive readings at least 4 hours apart, treatment should be considered.

Research questions

1. When should blood pressure be monitored in the first trimester of pregnancy? (Informed Recommendation 5)
2. How is blood pressure monitored in pregnancy? (Beyond scope)
3. What is the diagnostic test accuracy of measuring diastolic and systolic blood pressure, and mean arterial pressure in pregnancy and the significance of an increase of 15mmHg from baseline? (Informed narrative)
4. What would be the benefits or harms of intervention strategies? (Specific to pre-eclampsia)
5. What pre-existing medical conditions affect blood pressure in the first trimester of pregnancy? (Informed narrative)
6. What is the psychological impact of hypertension screening? (Informed narrative)
7. What are the additional needs of Aboriginal and Torres Straight Islander women? (No evidence identified)

Search Strategy

Databases searched: Medline; Embase; Cochrane Database of systematic Reviews.
Date of searches: December 2010; March 2011
Limits: English language
Publication dates for searches: 1. January 2003 – December 2010
2. December 2010 – March 2011

Review findings

1&2. There is minimal low level evidence on how or when to take blood pressures in the first trimester and none to refute the NICE 2003 recommendations.
3. The 2 level IV studies identified informed the narrative but did not alter the NICE recommendations.
4. The 2 level II, 6 level III-2, 4 level III-3 and 1 level IV studies identified reported conflicting results on the accuracy of blood pressure measurement in predicting pre-eclampsia. However, the presence of risk factors and/or blood pressure recordings raised above the norm during the first trimester are inextricably linked with later pregnancy pre-eclampsia (as well as pre-existing conditions, see 5 below) and should not be overlooked.
5. 1 level II and 3 level IV studies informed the narrative but did not alter the NICE recommendations.
6. 1 level II studies and 1 level IV study informed the narrative but did not alter the NICE recommendations.
7. No evidence identified.
There is insufficient new evidence to justify changing the NICE recommendations.

EAC recommendation

5. Measure blood pressure at a woman’s first antenatal visit to identify existing high blood pressure.

Evidence supporting recommendations (see Section 7.3.5)

Brown et al 2005; Cnossen et al 2008; Conde-Agudelo et al 2004; Emonts et al 2008; Miller et al 2007; Nijdam et al 2010; Onwudiwe et al 2008; Poon et al 2008; 2009

Grading of evidence — Recommendation 5

Evidence base - B
Consistency - B
Clinical impact - B
Generalisablity - B
Applicability - A
Recommendation - B
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Proteinuria

NICE recommendations

NICE did not cover proteinuria as a separate topic in 2003 or the 2008 update. All NICE references have been extracted from chapters on hypertensive disorders of pregnancy and/or pre-eclampsia.
Whenever blood pressure is measured in pregnancy, a urine sample should be tested at the same time for proteinuria. Research is needed to determine the optimal frequency and timing of blood pressure measurement and on the role of screening for proteinuria.
Use an automated reagent-strip reading device or a spot urinary protein:creatinine ratio for estimating proteinuria in a secondary care setting.

Research questions

1. What is the diagnostic test accuracy for proteinuria testing in the first trimester? (Informed Recommendation 6)
2. What would be the benefits or harms of testing for proteinuria in the first trimester? (No studies identified)
3. How is testing for proteinuria in the first trimester predictive of later pregnancy complications? (Informed narrative)

Search Strategy

Databases searched: Medline; Embase; Psychinfo; Cochrane Database of Systematic Reviews, Australasian Medical Index.
Date of search: December 2010
Limits: English language
Publication dates for search: January 2003 – December 2010

Review findings

1. The 1 level I study, 9 level III-2 studies, 3 level III-3 and 4 level IV studies identified found urine collection tests, protein:creatine ratio and automated dipstick analysis to be more accurate that visual inspection of urinary dipsticks.
2. No studies identified.
3. Two level II studies, 1 level III-2 study, 1 level III-3 study and 3 level IV studies suggest that proteinuria in the first trimester does not predict pre-eclampsia and subsequent testing should be confined to those with other risk factors such as existing or newly diagnosed hypertension, new or pre-existing kidney disease.

EAC recommendation

6. For point-of-care testing, use an automated analyser if available, as visual inspection of a urinary dipstick is the least accurate method to detect true proteinuria.

Evidence supporting recommendations (see Section 7.4.6)

Abebe et al 2008; Cote et al 2008a; 2008b; Davey & MacGillivray 1988; Dwyer et al 2008; Gangaram et al 2005; Gangaram et al 2009a; 2009b; Kyle et al 2008; Meads et al 2008; Phelan et al 2004; Price et al 2005; Risberg et al 2004; Rizk et al 2007; Rodriguez- Thompson & Lieberman 2001; Schubert et al 2006; Shennan & Waugh 2003; Waugh et al 2004; 2005

Grading of evidence — Recommendation 6

Evidence base - B
Consistency - B
Clinical impact - C
Generalisablity - A
Applicability - A
Recommendation - B

Consensus-based recommendations

iii. Routinely offer testing for proteinuria at the first antenatal visit, regardless of stage of pregnancy.
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Psychosocial factors affecting mental health

Consensus-based recommendations

Consensus-based recommendation iv is based on beyondblue (2011) Clinical Practice Guidelines on Depression and Related Disorders in the Perinatal Period Good Practice Point 7. The systematic literature review included a research question on the assessment of psychosocial factors but identified insufficient evidence to support a recommendation.

iv. As early as practical in pregnancy, ask all women questions about psychosocial factors. If a woman affirms the presence of psychosocial factors, ask whether she would like help with any of these issues.

Depression and anxiety

Recommendation

Recommendation 7 is based on beyondblue (2011) Clinical Practice Guidelines on Depression and Related Disorders in the Perinatal Period Recommendation 2, which was informed by the systematic literature review and graded in accordance with NHMRC Levels of Evidence and Grades for Recommendations for Developers of Guidelines (NHMRC 2009).

7. Use the Edinburgh Postnatal Depression Scale as a component of the assessment of all women for symptoms of depression in the antenatal period.

Consensus-based recommendations

Consensus-based recommendation v is based on beyondblue (2011) Clinical Practice Guidelines on Depression and Related Disorders in the Perinatal Period Good Practice Point 9. The systematic literature review included a clinical question on using tools to detect anxiety but identified insufficient evidence to support a recommendation..

v. Be aware that women who score 13 or more on the Edinburgh Postnatal Depression Scale (EPDS) may be experiencing anxiety, either alone or with depression. Base decisions about further assessment on the woman’s answers to questions 3, 4 and 5 of the EPDS and her response to enquiry about ‘worrying’.

Domestic violence

NICE recommendations

None

Research questions

1. What do health professionals need to do to identify women at risk from domestic violence? (Informed Recommendation 8)
2. Is routine enquiry about domestic violence acceptable to women? (Informed Consensus-based recommendation vi)
3. Is routine enquiry about domestic violence acceptable to clinicians? (Informed Consensus-based recommendation vii)
4. What interventions in a health care setting are effective for assisting women affected by domestic violence? (Informed narrative)
5. What do health professionals need to do to identify Aboriginal and Torres Strait Islander women experiencing domestic violence? (No studies identified)
6. Is routine enquiry about domestic violence acceptable to Aboriginal and Torres Strait Islander women? (No studies identified)
7. Is routine enquiry about domestic violence acceptable to clinicians caring for Aboriginal and Torres Strait Islander women? (No studies identified)
8. What interventions in a health care setting are effective for assisting Aboriginal and Torres Strait Islander women affected by domestic violence? (Informed narrative)

Search Strategy

Databases searched: Medline + Pub Med, EMBASE, CINAHL, NHS Evidence, SIGLE, JBI, COCHRANE, PsycINFO, LILACS, CONTROLLED TRIALS, NDLTD, Informit
Date of search: February 2011
Limits: English language
Publication dates for search: January 2003 – February 2011
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Review findings


1. 1 level I, 1 level II and 5 level III-2 studies supported enquiry about domestic violence.
2. 6 level III-2 and 1 qualitative study suggested that enquiry is acceptable to women.
3. 1 level II, 15 level III-2, 2 level IV and 6 qualitative studies highlighted barriers to health professionals enquiring about domestic violence and informed development of the narrative.
4. 2 level II studies included in narrative.
5. No studies identified. Advice provided by Working Group for Aboriginal and Torres Strait Islander Women’s Antenatal Care.
6. No studies identified. Advice provided by Working Group for Aboriginal and Torres Strait Islander Women’s Antenatal Care.
7. No studies identified. Advice provided by Working Group for Aboriginal and Torres Strait Islander Women’s Antenatal Care.
8. 1 qualitative study identified. Advice provided by Working Group for Aboriginal and Torres Strait Islander Women’s Antenatal Care.

EAC recommendation

8. At the first antenatal visit, explain to all women that asking about domestic violence is a routine part of antenatal care and enquire about each woman’s exposure to domestic violence.

Evidence supporting recommendations (see Section 7.7.5)

Ameh et al 2008; Bacchus et al 2003; Hegarty et al 2007; Kataoka et al 2004; Keeling & Birch 2004; Mezey et al 2005; Moonesinghe et al 2004; O’Reilly et al 2010; Renker & Tonkin 2006; Roelens 2010; Roelens et al 2008; Salmon et al 2006; Stenson et al 2005; Taft 2002; Taft et al 2004; Walsh 2008; Webster & Holt 2004

Grading of evidence — Recommendation 8

Evidence base - B
Consistency - A
Clinical impact - B
Generalisablity - B
Applicability - A
Recommendation - B

Consensus-based recommendations

vi. Ask about domestic violence when alone with the woman, tailoring the approach to her individual situation and your own skills and experience (eg use open-ended questions about her perception of safety at home or use an assessment tool).
vii. Be aware that training programs improve the confidence and competency of health professionals in identifying and caring for women experiencing domestic violence.

Nausea and vomiting

NICE recommendation

Women should be informed that most cases of nausea and vomiting in pregnancy will resolve spontaneously within 16 to 20 weeks and that nausea and vomiting are not usually associated with a poor pregnancy outcome. If a woman requests or would like to consider treatment, the following interventions appear to be effective in reducing symptoms:
  • non-pharmacological: ginger, P6 (wrist) acupressure
  • pharmacological: antihistamines.
Information about all forms of self-help and nonpharmacological treatments should be made available for pregnant women who have nausea and vomiting. [PP]

Research question

Are there effective interventions to treat nausea and vomiting in pregnancy and what are the perinatal outcomes associated with these interventions? (Informed narrative)
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Search Strategy

Databases searched: Medline; Embase; Google Scholar
Date of searches: November 2009; November 2010
Limits: English language
Publication dates for searches:
1. January 2003 – August 2009
2. January 2008 – November 2010

Review findings

While there is a growing body of evidence in support of the use of various interventions for symptoms of nausea and vomiting, as yet there remain insufficient data to recommend any particular treatment. The recent Cochrane strengthens the evidence base but found insufficient evidence to recommend specific interventions or alter the NICE practice point.

Constipation

NICE recommendation

Women who present with constipation in pregnancy should be offered information regarding diet modification, such as bran or wheat fibre supplementation. [A]

Research questions

1. What is the prevalence of constipation in pregnant women? (Informed narrative)
2. What interventions help relieve constipation and are safe in pregnancy? (Informed Recommendations 9 and 10)

Search Strategy

Databases searched: Medline; Embase; Psychinfo; Cochrane Database of Systematic Reviews, Australasian Medical Index.
Date of searches: March 2009; November 2010
Limits: English language
Publication dates for searches: 1. January 2003 – March 2009
2. January 2008 – November 2010

Review findings

1. 4 level IV studies informed the narrative.
2. The 1 level I study (a Cochrane review) identified was consistent with the NICE recommendation. This review, 1 level III-3 study and 1 level IV study also supported a recommendation on laxatives.

EAC recommendations

9. Offer women who present with constipation in pregnancy information about increasing dietary fibre intake and taking bran or wheat fibre supplementation.
10. Advise women who choose to take laxatives that preparations that stimulate the bowel are more effective than those that add bulk but may cause more adverse effects such as diarrhoea and abdominal pain.

Evidence supporting recommendations (see Section 7.9.5)

Recommendation 9 — Jewell & Young 2010
Recommendation 10 — Jewell & Young 2010; Neri et al 2004; Vasquez 2008
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Grading of evidence — Recommendation 9

Evidence base - C
Consistency - NA
Clinical impact - B
Generalisablity - B
Applicability - A
Recommendation - C

Grading of evidence — Recommendation 10

Evidence base - C
Consistency - C
Clinical impact - B
Generalisablity - B
Applicability - A
Recommendation - C