Antenatal care

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(1)National Collaborating Centre for Women’s and Children’s Health. Antenatal care routine care for the healthy pregnant woman. Clinical Guideline March 2008 Funded to produce guidelines for the NHS by NICE.

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(3) Antenatal care routine care for the healthy pregnant woman National Collaborating Centre for Women’s and Children’s Health Commissioned by the National Institute for Health and Clinical Excellence March 2008. This is a partial update of the 2003 guideline. New or amended sections are indicated by a grey bar in the margin.. RCOG Press.

(4) Published by the RCOG Press at the Royal College of Obstetricians and Gynaecologists, 27 Sussex Place, Regent’s Park, London NW1 4RG www.rcog.org.uk Registered charity no. 213280 First published 2008, revised reprint 2008 (page 98) 2nd edition © 2008 National Collaborating Centre for Women’s and Children’s Health 1st edition published in 2003 No part of this publication may be reproduced, stored or transmitted in any form or by any means, without the prior written permission of the publisher or, in the case of reprographic reproduction, in accordance with the terms of licences issued by the Copyright Licensing Agency in the UK [www.cla.co.uk]. Enquiries concerning reproduction outside the terms stated here should be sent to the publisher at the UK address printed on this page. The use of registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant laws and regulations and therefore for general use. While every effort has been made to ensure the accuracy of the information contained within this publication, the publisher can give no guarantee for information about drug dosage and application thereof contained in this book. In every individual case the respective user must check current indications and accuracy by consulting other pharmaceutical literature and following the guidelines laid down by the manufacturers of specific products and the relevant authorities in the country in which they are practising. ISBN 978-1-904752-46-2 NCC-WCH Editor: Andrew Welsh Original design: FiSH Books, London Typesetting: Andrew Welsh Proofreading: Katharine Timberlake (Reedmace Editing) Index: Jan Ross (Merrall-Ross (Wales) Ltd) Printed by Henry Ling Ltd, The Dorset Press, Dorchester DT1 1HD.

(5) Contents vi vi vi vi vii viii viii viii xii xvi 1 1 1 2 3 3 3 4 12 12 13 25 26 27 37 37 37 58 67 67 67 69 69 70 73 78 82 82 82 82 83 84 92 93 93 93 94 95 95 101 101 102 103. iii. 2008 update. Guideline Development Group membership and acknowledgements Original (2003) version: Guideline Development Group Acknowledgments Stakeholder organisations Peer reviewers 2008 update: Guideline Development Group Acknowledgments Stakeholder organisations Abbreviations Glossary of terms 1 Introduction 1.0 Introduction 1.1 Aim of the guideline 1.2 Areas outside the remit of the guideline 1.3 For whom is the guideline intended? 1.4 Who has developed the guideline? 1.5 Who has developed the guideline update? 1.6 Guideline methodology 2 Summary of recommendations and care pathway 2.1 Key priorities for implementation (key recommendations) 2.2 Summary of recommendations 2.3 Key priorities for research 2.4 Additional research recommendations 2.5 Care pathway 3 Woman-centred care and informed decision making 3.1 Introduction 3.2 Provision of information 3.3 Antenatal classes 4 Provision and organisation of care 4.1 Who provides care? 4.2 Continuity of care 4.3 Where should antenatal appointments take place? 4.4 Documentation of care 4.5 Frequency of antenatal appointments 4.6 Gestational age assessment 4.7 What should happen at antenatal appointments? 5 Lifestyle considerations 5.1 Physiological, psychosocial and emotional changes in pregnancy 5.2 Maternity health benefits 5.3 Working during pregnancy 5.4 Dietary information and education 5.5 Nutritional supplements 5.6 Food-acquired infections 5.7 Prescribed medicines 5.8 Over-the-counter medicines 5.9 Complementary therapies 5.10 Exercise in pregnancy 5.11 Sexual intercourse in pregnancy 5.12 Alcohol and smoking in pregnancy 5.13 Cannabis use in pregnancy 5.14 Air travel during pregnancy 5.15 Car travel during pregnancy 5.16 Travelling abroad during pregnancy.

(6) 2008. 2008 update. 2008. Antenatal care. 6 Management of common symptoms of pregnancy 6.1 Nausea and vomiting in early pregnancy 6.2 Heartburn 6.3 Constipation 6.4 Haemorrhoids 6.5 Varicose veins 6.6 Vaginal discharge 6.7 Backache 6.8 Symphysis pubis dysfunction 6.9 Carpal tunnel syndrome 7 Clinical examination of pregnant women 7.1 Measurement of weight and body mass index 7.2 Breast examination 7.3 Pelvic examination 7.4 Female genital mutilation 7.5 Domestic violence 7.6 Psychiatric screening 8 Screening for haematological problems 8.1 Anaemia 8.2 Blood grouping and red cell alloantibodies 8.3 Screening for haemoglobinopathies (sickle cell disease and thalassaemia) 9 Screening for fetal anomalies 9.1 Screening for structural anomalies 9.2 Screening for Down’s syndrome 10 Screening for infections 10.1 Asymptomatic bacteriuria 10.2 Asymptomatic bacterial vaginosis 10.3 Chlamydia trachomatis 10.4 Cytomegalovirus 10.5 Hepatitis B virus 10.6 Hepatitis C virus 10.7 HIV 10.8 Rubella 10.9 Streptococcus group B 10.10 Syphilis 10.11 Toxoplasmosis 11 Screening for clinical problems 11.1 Gestational diabetes 11.2 Pre-eclampsia 11.3 Preterm birth 11.4 Placenta praevia 12 Fetal growth and wellbeing 12.1 Introduction and background 12.2 Diagnostic value for predicting SGA babies 12.3 Diagnostic value for predicting LGA babies 12.4 Effectiveness studies 12.5 Health economics evidence 12.6 Fetal wellbeing 13 Management of specific clinical conditions 13.1 Pregnancy after 41 weeks 13.2 Pregnancy after 42 weeks 13.3 Breech presentation at term 14 Antenatal assessment tool 14.1 Introduction and background 14.2 Systematic review of the evidence 14.3 Developing an antenatal assessment tool Appendix A Declarations of interest Appendix B Economic model: asymptomatic bacteriuria screening programme Appendix C Economic model: streptococcus group B screening programme Appendix D Economic model: syphilis screening programme. iv. 106 106 108 109 110 110 111 112 113 113 114 114 115 115 116 117 118 120 120 121 122 134 134 154 180 180 183 184 193 194 194 195 197 198 200 202 205 205 218 228 251 253 253 255 265 267 274 275 278 278 279 280 282 282 282 286 290 292 294 295.

(7) 297 305 331 336 337 338 339 339 341 344 345 347 348 348 349 350 351 353 357 357 358 361 364 365 365 366 368 369 380 397 408 CD-ROM CD-ROM CD-ROM. . 2008 update. Appendix E Economic model: screening for congenital cardiac malformations Appendix F Economic model: screening and treatment of gestational diabetes Appendix G Economic model: monitoring fetal growth Appendix H Training and equipment standards for ultrasound screening in pregnancy Appendix I Further information Appendix J Family origin questionnaire Appendix K Deleted material from the 2003 version 2.1 Summary of recommendations 2.3 Algorithm – Antenatal care: routine care for the healthy pregnant woman 3.1 Provision of information 3.2 Antenatal education 4.6 Gestational age assessment: LMP and ultrasound 5.5 Nutritional supplements 5.12 Alcohol and smoking in pregnancy 8.2 Screening for sickle cell disorders and thalassaemia 9 Screening for fetal anomalies 9.1 Screening for structural anomalies 9.2 Screening for Down’s syndrome 10.1 Asymptomatic bacteriuria 10.3 Chlamydia trachomatis 11.1 Gestational diabetes mellitus 11.2 Pre-eclampsia 11.3 Preterm birth 11.4 Placenta praevia 12.2 Measurement of symphysis–fundal distance 12.7 Umbilical and uterine artery Doppler ultrasound 15 Auditable standards Appendix 1 References (2003 version) References (2008 update) Index Search strategies Excluded studies Evidence tables. 2008 update. Contents.

(8) Guideline Development Group membership and acknowledgements Original (2003) version Guideline Development Group Peter Brocklehurst Belinda Ackerman Brian Cook Joanie Dimavicius Helen Edwards Gill Gyte Shahid Husain Gwyneth Lewis Tim Overton Gill Roberts Stephen Robson Julia Sanders Anne White Jane Thomas Sue Lee Jennifer Gray Natalie Terry Hannah Rose Douglas Dimitra Lambrelli. Group Leader Midwife General Practitioner Consumer Radiographer Consumer Neonatologist Confidential Enquiry into Maternal Deaths Obstetrician RCOG Patient Information Specialist Obstetrician Midwife General Practitioner Director NCC-WCH Research Fellow NCC-WCH Informatics Specialist NCC-WCH Administrative support NCC-WCH Health Economist, London School of Hygiene and Tropical Medicine Health Economist London School of Hygiene and Tropical Medicine. Acknowledgments Additional support was also received from: • David Asomani, Anna Burt, Heather Brown, Susan Davidson, Gregory Eliovson, Susan Murray and Alex McNeil at the National Collaborating Centre for Women’s and Children’s Health. • Stravros Petrou at the National Perinatal Epidemiology Unit and Kirsten Duckitt at the John Radcliffe Hospital, Oxford. • Members of the previous Antenatal Care Guideline Development Group: John Spencer (Chairman), J Bradley, Jean Chapple, R Cranna, Marion Hall, Marcia Kelson, Catherine McCormack, Ralph Settatree, Lindsay Smith, L Turner, Martin Whittle, Julie Wray. • The Patient Involvement Unit, whose glossary we have amended for use in this guideline. • The Three Centres Consensus Guidelines on Antenatal Care, Mercy Hospital for Women, Monash Medical Centre (Southern Health) and The Royal Women’s Hospital (Women’s & Children’s Health), Melbourne 2001, whose work we benefited from in the development of this guideline.. Stakeholder organisations Action on Pre-Eclampsia (APEC) Antenatal Results and Choices Association for Continence Advice (ACA) Association for Improvements in Maternity Services (AIMS) vi.

(9) Guideline Development Group membership and acknowledgements. Association of Radical Midwives Association of the British Pharmaceuticals Industry(ABPI) Aventis Pasteur MSD Brighton Healthcare NHS Trust British Association of Paediatric Surgeons British Association of Perinatal Medicine British Dietetic Association British Maternal and Fetal Medicine Society British Medical Association British National Formulary British Psychological Society BUPA Chartered Society of Physiotherapy CIS’ters Department of Health Evidence based Midwifery Network Faculty of Public Health Medicine Gateshead Primary Care Trust General Medical Council Group B Strep Support Health Development Agency Hospital Infection Society Isabel Medical Charity Maternity Alliance Mental Health Foundation Monmouthshire Local Health Group National Childbirth Trust NHS Quality Improvement Scotland Nottingham City Hospital Obstetric Anaesthetists Association Royal College of General Practitioners Royal College of General Practitioners Wales Royal College of Midwives Royal College of Nursing Royal College of Obstetricians and Gynaecologists Royal College of Paediatrics and Child Health Royal College of Pathologists Royal College of Psychiatrists Royal College of Radiologists Royal Pharmaceutical Society of Great Britain Royal Society of Medicine Scottish Intercollegiate Guidelines Network (SIGN) Sickle Cell Society Society and College of Radiographers STEPS Survivors Trust Twins and Multiple Births Association (TAMBA) UK Coalition of People Living with HIV and AIDS UK National Screening Committee UK Pain Society United Kingdom Association of Sonographers Victim Support Welsh Assembly Government (formerly National Assembly for Wales) West Gloucestershire Primary Care Trust Young Minds. Peer reviewers Susan Bewley, Leanne Bricker, Howard Cuckle, Andrew Dawson, Viv Dickinson, Grace Edwards, Jason Gardosi, Duncan Irons, Deirdre Murphy, Tim Reynolds, Jilly Rosser, Lindsay Smith, John Spencer, Pat Tookey, Derek Tuffnell, Gavin Young. vii.

(10) Antenatal care. 2008 update Guideline Development Group GDG members Rhona Hughes Jane Anderson Chris Barry Marie Benton Jennifer Elliott Nina Khazaezadeh Rachel Knowles Tim Overton Katie Yiannouzis. Group Leader Ultrasound Radiographer General Practitioner Service User Representative Service User Representative Consultant Midwife and Supervisor of Midwives Medical Research Council Clinical Public Health Research Fellow Consultant Obstetrician Head of Midwifery. 2008 update. National Collaborating Centre for Women’s and Children’s Health (NCC-WCH) staff Rupert Franklin Eva Gautam-Aitken Paul Jacklin Rajesh Khanna Rintaro Mori Francesco Moscone Debbie Pledge Jeff Round Anuradha Sekhri Roz Ullman Martin Whittle. Work-Programme Coordinator Work-Programme Coordinator Senior Health Economist Senior Research Fellow Research Fellow Health Economist Senior Information Scientist Health Economist Research Fellow Senior Research Fellow Co-Director in Women’s Health. External advisers Guy Rooney Anne Longton Fiona Ford Jane Hawdon. Genitourinary Medicine Specialist Health Visitor Dietician Consultant Neonataologist. Acknowledgments Additional support was also received from: • Anna Bancsi, Angela Kraut, Moira Mugglestone and Martin Dougherty at the NCC-WCH • Allison Streetly, Programme Director for the NHS Sickle Cell and Thalassaemia Screening Programme. • Andrew Welsh, freelance guideline editor, whose editorial support was invaluable in the production of this guideline. • Group Dynamics, who provided the voting equipment for the Assessment Tool consensus meeting.. Stakeholder organisations Academic Division of Midwifery, University of Nottingham Action on Pre-Eclampsia Addenbrooke’s NHS Trust All Wales Birth Centre Group Antenatal Screening Wales Association for Psychoanalytic Psychotherapy in the NHS Association for Spina Bifida & Hydrocephalus (ASBAH) Association of Breastfeeding Mothers Association of British Clinical Diabetologists Association of Chartered Physiotherapists in Women’s Health viii.

(11) Guideline Development Group membership and acknowledgements. 2008 update. Association of Medical Microbiologists Association of the British Pharmaceuticals Industry (ABPI) Baby Lifeline Barnsley Acute Trust Barnsley PCT BDF Newlife (Birth Defects Foundation) Bedfont Scientific Ltd Bedfordshire PCT Berkshire Healthcare NHS Trust Birmingham Women’s Healthcare Trust Birth Trauma Association Bradford & Airedale PCT Bradford Teaching Hospitals NHS Foundation Trust Brighton & Sussex University Hospitals Trust Bristol Health Services Plan British Association for Counselling and Psychotherapy British Dietetic Association British HIV Association (BHIVA) British Hypertension Society British Maternal and Fetal Medicine Society British National Formulary (BNF) British Psychological Society Calderdale PCT CASPE CEMACH Chartered Society of Physiotherapy Chelsea & Westminster NHS Foundation Trust Chronic Conditions Collaborating Centre CIS’ters CO-Awareness Commission for Social Care Inspection Community Practitioners and Health Visitors Association Connecting for Health Cotswold and Vale PCT Croydon PCT Cytyc UK Ltd Department of Health, Social Security and Public Safety of Northern Ireland Derbyshire Mental Health Services NHS Trust Det Norske Veritas – NHSLA Schemes Doula UK Down’s Syndrome Association Dudley Group of Hospitals NHS Trust English National Forum of LSA Midwifery Officers Epsom & St Helier University Hospitals NHS Trust Evidence-based Midwifery Network Faculty of Family Planning and Reproductive Health Care Faculty of Public Health Foundation for the Study of Infant Deaths Gateshead PCT Gloucestershire Acute Trust Gloucestershire Hospitals NHS Foundation Trust Group B Strep Support Guy’s and St Thomas’ NHS Foundation Trust Health Protection Agency Healthcare Commission Homerton University Hospital NHS Foundation Trust Huntleigh Healthcare King’s College Hospital NHS Trust. ix.

(12) 2008 update. Antenatal care. Liverpool PCT Liverpool Women’s Hospital NHS Trust Luton and Dunstable Hospital NHS Trust Mast Diagnostics Medicines and Healthcare products Regulatory Agency (MHRA) Mid and West Regional MSLC Milton Keynes PCT Monica Healthcare Ltd MRC Centre of Epidemiology for Child Health National Childbirth Trust National Chlamydia Screening Programme National Patient Safety Agency National Public Health Service – Wales NHS Direct NHS Health and Social Care Information Centre NHS Quality Improvement Scotland NHS Sickle Cell and Thalassemia Screening Programme North Tees and Hartlepool NHS Trust Northwest London Hospitals NHS Trust Nutrition Society Obstetric Anaesthetists Association Partnerships for Children, Families, Women and Maternity Pelvic Partnership PERIGON (formerly the NHS Modernisation Agency) Phoenix Partnership PNI ORG UK Positively Women Post Natal Illness Organisation (PNI) Primary Care Pharmacists’ Association PRIMIS+ Princess Alexandra Hospital NHS Trust Queen Mary’s Hospital NHS Trust (Sidcup) Regional Maternity Survey Office Regional Public Health Group – London Royal College of General Practitioners Royal College of Midwives Royal College of Nursing Royal College of Obstetricians and Gynaecologists Royal College of Paediatrics and Child Health Royal College of Pathologists Royal College of Psychiatrists Royal College of Radiologists Royal Liverpool Children’s Trust Royal Society of Medicine Salford Royal Hospitals NHS Foundation Trust Salisbury NHS Foundation Trust Sandwell and West Birmingham NHS Trust Sanofi Pasteur MSD Scottish Executive Health Department Scottish Intercollegiate Guidelines Network (SIGN) Sefton PCT Sheffield South West PCT Sheffield Teaching Hospitals NHS Trust Sickle Cell & Thalassaemia Association of Counsellors Sickle Cell Society Society and College of Radiographers Survivors Trust TIPS Limited. .

(13) Guideline Development Group membership and acknowledgements. 2008 update. UK Coalition of People Living with HIV & AIDS UK Forum on Haemoglobin Disorders UK National Screening Committee UK Newborn Screening Programme Centre UK Thalassaemia Society UNICEF Baby Friendly Initiative United Lincolnshire Hospitals NHS Trust University College London Hospitals NHS Foundation Trust University College London Hospitals NHS Trust University Hospitals of Leicester Victim Support Welsh Assembly Government Welsh Scientific Advisory Committee (WSAC) West Middlesex University Hospital NHS Trust Western Cheshire PCT Wiltshire PCT Wirral University Hospital Teaching NHS Trust Women’s Health Research Group Worcestershire Acute NHS Trust Worthing and Southlands Hospital NHS Trust Worthing Hospital Wyre Forest PCT York NHS Trust Yorkshire and Humber Local Supervisory Authority. xi.

(14) 2008 update. Abbreviations AC ACHOIS ACOG ACTH ADA AFG AFI AFP AIDS ALPHA ANC APEC APH ASB BD BERR BMC BMI BP BPD BV BW CAMP cBG120 min CDSC CEGEN cFBG CFGC cfu/ml CHO CI CINAHL CMV CNS COMA CPC CRL CRP CS CTG DA DARE df DFA DNA DR DS Dx eAg EB xii. abdominal circumference Australian Carbohydrate Intolerance Study in Pregnant Women American College of Obstetricians and Gynecologists adrenocorticotrophic hormone American Diabetes Association adequate fetal growth amniotic fluid index alpha-fetoprotein acquired immune deficiency syndrome Antenatal Psychosocial Health Assessment antenatal care Action on Pre-eclampsia antepartum haemorrhage asymptomatic bacteriuria twice a day Department for Business, Enterprise and Regulatory Reform bone mineral content body mass index blood pressure biparietal diameter or bronchopulmonary dysplasia bacterial vaginosis birthweight Christie, Atkinson, Munch, Peterson test capillary blood glucose 120 minutes after glucose load Communicable Disease Surveillance Centre Confidential Enquiry into Counselling for Genetic Disorders capillary fasting blood glucose customised fetal growth chart colony-forming units per millilitre carbohydrate confidence interval Cumulative Index to Nursing and Allied Health Literature cytomegalovirus central nervous system Committee on Medical Aspects of Food Policy choroid plexus cyst crown–rump length C-reactive protein caesarean section cardiotocography direct agglutination test Database of Abstracts and Reviews of Effectiveness degrees of freedom direct fluorescent antibody test deoxyribonucleic acid detection rate Down’s syndrome Diagnosis hepatitis e antigen elementary body.

(15) Abbreviations. external cephalic version European Economic Area estimated fetal weight enzyme immunoassay evidence level enzyme-linked immunosorbent assay early-onset group B streptococcus Edinburgh Postnatal Depression Scale external intermittent pneumatic compression European Union full blood count fetal fibronectin female genital mutilation fetal growth restriction femtolitre (10−15 litres) femur length fasting plasma glucose false positive rate fluorescent treponemal antibody – absorbed test gestational age group B streptococcus glucose challenge test gestational diabetes Guideline Development Group gestational diabetes mellitus good practice point glucose tolerance test history of Hospital Anxiety and Depression Scale haemoglobin hepatitis B immune globulin hepatitis B surface antigen hepatitis B virus head circumference human chorionic gonadotrophin (can be total or free beta) beta-human chorionic gonadotrophin hepatitis C virus haemolytic disease of the newborn Health Economic Evaluations Database haemolysis, elevated liver enzymes and low platelet count human immunodeficiency virus Health Protection Agency high-performance liquid chromatography health sector initiative hypertension Health Technology Assessment International Classification of Diseases, 9th edition incremental cost-effectiveness ratio inadequate fetal growth impaired glucose tolerance interleukin intramuscular(ly) interactive multimedia decision aid intrapartum care intimate partner violence international unit intrauterine growth restriction latex agglutination test. 2008 update. ECV EEA EFW EIA EL ELISA EOGBS EPDS EPIC EU FBC FFN FGM FGR fl FL FPG FPR FTA-abs GA GBS GCT GD GDG GDM GPP GTT H/O HADS Hb HBIG HBsAg HBV HC hCG β-hCG HCV HDN HEED HELLP HIV HPA HPLC HSI HT HTA ICD-9 ICER IFG IGT IL IM IMDA IPC IPV IU IUGR LA. xiii.

(16) 2008 update. Antenatal care. LBW LCR LE LGA LMP LR LR− LR+ LSHTM MCH MCV MeSH MIDIRS MMIC MoM MOMP MSAFP MSHCG MSS MSU MTCT NCC-WCH NCRSP NEC NFG NHS EED NHS NICE NICU NNT NPI NPV NS NSC NSF NT NTD OGTT OH 25-OHD ONS OR OTC oz PAI PAPP-A PCR PCT PE pg PHLS PI PIH PPV PROM PTD QID RBC . xiv. low birthweight ligase chain reaction leucocyte esterase large for gestational age last menstrual period likelihood ratio negative likelihood ratio positive likelihood ratio London School of Hygiene & Tropical Medicine mean corpuscular haemoglobin mean corpuscular volume medical subject headings Midwives Information and Resource Service Multidimensional Measure of Informed Choice multiples of the median major outer membrane protein maternal serum alpha-fetoprotein maternal serum beta-human chorionic gonadotrophin maternal serum screening midstream urine sample mother-to-child transmission National Collaborating Centre for Women’s and Children’s Health National Congenital Rubella Surveillance Programme necrotising enterocolitis normal fetal growth NHS Economic Evaluations Database National Health Service National Institute for Health and Clinical Excellence neonatal intensive care unit number needed to treat Neonatal Perception Inventory negative predictive value not significant (UK) National Screening Committee National Service Framework nuchal translucency neural tube defect oral glucose tolerance test oligohydramnios 25-hydroxyvitamin D Office for National Statistics odds ratio over-the-counter fluid ounce (28.41 ml) Prenatal Attachment Inventory pregnancy-associated plasma protein-A polymerase chain reaction primary care trust pre-eclampsia picogram (10−12 grams) Public Health Laboratory Service pulsatility index pregnancy-induced hypertension positive predictive value preterm rupture of the membranes preterm delivery four times a day red blood cell.

(17) Abbreviations. random blood glucose Royal College of Obstetricians and Gynaecologists randomised controlled trial rhesus D recombinant immunoblot assay ribonucleic acid receiver operating characteristic retinopathy of prematurity random plasma glucose rapid plasmin reagin test relative risk reagent strip testing systolic/diastolic Scientific Advisory Committee on Nutrition standard deviation socio-economic(ally) symphysis–fundal height small for gestational age Scottish Intercollegiate Guidelines Network specificity symphysis pubis dysfunction spontaneous preterm birth sensitivity Spielberger State-Trait Anxiety Inventory trisomy 21, 18 or 13 three times a day tranposition of the great arteries Treponema pallidum haemagglutination assay transvaginal sonography unconjugated estriol ultra-high-temperature processing United Kingdom United States Centers for Disease Control and Prevention ultrasound US Preventive Services Task Force ultrasound scan urinary tract infection Venereal Disease Research Laboratory (test for syphilis) vaginal examination World Health Organization weighted mean difference. 2008 update. RBG RCOG RCT RhD RIBA RNA ROC ROP RPG RPR RR RST S/D SACN SD SE SFH SGA SIGN SP SPD SPTB ST STAI T 21/18/13 TDS TGA TPHA TVS uE3 UHT UK US CDC US USPSTF USS UTI VDRL VE WHO WMD. xv.

(18) 2008 update. Glossary of terms Bias. Influences on a study that can lead to invalid conclusions about a treatment or intervention. Bias in research can make a treatment look better or worse than it really is. Bias can even make it look as if the treatment works when it actually doesn’t. Bias can occur by chance or as a result of systematic errors in the design and execution of a study. Bias can occur at different stages in the research process, e.g. in the collection, analysis, interpretation, publication or review of research data.. Blinding or masking. The practice of keeping the investigators or subjects of a study ignorant of the group to which a subject has been assigned. For example, a clinical trial in which the participating patients or their doctors are unaware of whether they (the patients) are taking the experimental drug or a placebo (dummy treatment). The purpose of ‘blinding’ or ‘masking’ is to protect against bias. See also double-blind study.. Body mass index (BMI). A person’s weight (in kilograms) divided by the square of their height (in metres). It is used as a measure of underweight, overweight or obesity.. Booking. The appointment where the woman enters the maternity care pathway, characterised by information giving and detailed history-taking to help the woman choose the most appropriate antenatal care pathway. Also includes measurement of height, weight, blood pressure and blood tests for determining blood group, rubella status and haemoglobin level. Blood and urine samples for screening may also be taken at booking after the woman has been well informed and has given her consent. The booking appointment follows the first contact with a health professional.. Case–control study. A study that starts with the identification of a group of individuals sharing the same characteristics (e.g. people with a particular disease) and a suitable comparison (control) group (e.g. people without the disease). All subjects are then assessed with respect to things that happened to them in the past, e.g. things that might be related to getting the disease under investigation. Such studies are also called retrospective as they look back in time from the outcome to the possible causes.. Case report (or case study) Detailed report on one patient (or case), usually covering the course of that person’s disease and their response to treatment. Case series. Description of several cases of a given disease, usually covering the course of the disease and the response to treatment. There is no comparison (control) group of patients.. Clinical effectiveness. The extent to which a specific treatment or intervention, when used under usual conditions, has a beneficial effect on the course or outcome of a disease compared with no treatment or routine care.. Clinical question. The term is sometimes used in guideline development to refer to the questions about treatment and care that are formulated in order to guide the search for research evidence.. Clinical trial. A research study conducted with patients which tests out a drug or other intervention to assess its effectiveness and safety. Each trial is designed to answer scientific questions and to find better ways to treat individuals with a specific disease. This general term encompasses controlled clinical trials and randomised controlled trials.. Cluster. A group of patients, rather than an individual, used as a basic unit for investigation. See also cluster randomisation.. Cluster randomisation. A study in which groups of individuals (eg. attending one GP surgery) are randomly allocated to intervention groups. See also cluster.. Cohort. A group of people sharing some common characteristic (e.g. patients with the same disease), followed up in a research study for a specified period of time.. xvi.

(19) Glossary of terms. Cohort study. An observational study that takes a group (cohort) of patients and follows their progress over time in order to measure outcomes such as disease or mortality rates and make comparisons according to the treatments or interventions that patients received. Thus within the study group, subgroups of patients are identified (from information collected about patients) and these groups are compared with respect to outcome, e.g. comparing mortality between one group that received a specific treatment and one group which did not (or between two groups that received different levels of treatment). Cohorts can be assembled in the present and followed into the future (a concurrent or prospective cohort study) or identified from past records and followed forward from that time up to the present (a historical or retrospective cohort study). Because patients are not randomly allocated to subgroups, these subgroups may be quite different in their characteristics and some adjustment must be made when analysing the results to ensure that the comparison between groups is as fair as possible.. Combined test. A battery of screening tests used together to determine the risk of the unborn baby having Down’s Syndrome. The tests are: a nuchal translucency ultrasound scan plus blood tests to measure levels of a beta human chorionic gonadotrophin and pregnancy-associated plasma protein-A. The test should be performed between 11 weeks 0 days and 13 weeks 6 days.. Confidence interval. A way of expressing certainty about the findings from a study or group of studies, using statistical techniques. A confidence interval describes a range of possible effects (of a treatment or intervention) that is consistent with the results of a study or group of studies. A wide confidence interval indicates a lack of certainty or precision about the true size of the clinical effect and is seen in studies with too few patients. Where confidence intervals are narrow they indicate more precise estimates of effects and a larger sample of patients studied. It is usual to interpret a ‘95%’ confidence interval as the range of effects within which we are 95% confident that the true effect lies.. Consensus methods. A variety of techniques that aim to reach an agreement on a particular issue. Formal consensus methods include Delphi or nominal group techniques, and consensus development conferences. In the development of a clinical guideline, consensus methods may be used where there is a lack of good research evidence.. Consistency. The extent to which the conclusions of a collection of studies used to support a guideline recommendation are in agreement with each other. See also homogeneity.. Control group. A group of patients recruited into a study that receives no treatment, a treatment of known effect, or a placebo (dummy treatment), in order to provide a comparison for a group receiving an experimental treatment, such as a new drug.. Controlled clinical trial (CCT). A study testing a specific drug or other treatment involving two (or more) groups of patients with the same disease. One (the experimental group) receives the treatment that is being tested, and the other (the comparison or control group) receives an alternative treatment, a placebo (dummy treatment) or no treatment. The two groups are followed up to compare differences in outcomes to see how effective the experimental treatment was. A CCT where patients are randomly allocated to treatment and comparison groups is called a randomised controlled trial.. Cost–benefit analysis. A type of economic evaluation where both costs and benefits of healthcare treatment are measured in the same monetary units. If benefits exceed costs, the evaluation would recommend providing the treatment.. Cost-effectiveness. A type of economic evaluation that assesses the additional costs and benefits of doing something different. In cost-effectiveness analysis, the costs and benefits of different treatments are compared. When a new treatment is compared with current care, its additional costs divided by its additional benefits is called the cost-effectiveness ratio. Benefits are measured in natural units, for example, cost per additional heart attack prevented.. Cost–utility analysis. A special form of cost-effectiveness analysis where benefit is measured in quality-adjusted life years (QALYs). A treatment is assessed in terms of its ability to extend or improve the quality of life.. Counselling. For the purpose of the guideline, ‘counselling’ is defined broadly as supportive listening, advice giving and information. The British Association for Counselling and Psychotherapy offers a more specific definition of counselling as a discrete psychological intervention (regular planned meetings of usually 50 minutes in length) which is facilitative, nondirective and/or relationship focused, with the content of sessions largely determined by the service user’.. xvii. 2008 update. Confounder or confounding Something that influences a study and can contribute to misleading findings if it is not variable/factor understood and appropriately dealt with..

(20) 2008 update. Antenatal care. Crossover study design. A study comparing two or more interventions in which the participants, upon completion of the course of one treatment, are switched to another. For example, for a comparison of treatments A and B, half the participants are randomly allocated to receive them in the order A, B and half to receive them in the order B, A. A problem with this study design is that the effects of the first treatment may carry over into the period when the second is given. Therefore a crossover study should include an adequate ‘wash-out’ period, which means allowing sufficient time between stopping one treatment and starting another so that the first treatment has time to wash out of the patient’s system.. Cross-sectional study. The observation of a defined set of people at a single point in time or time period – a snapshot. (This type of study contrasts with a longitudinal study, which follows a set of people over a period of time.). Customised fetal growth chart. The customised fetal growth chart (CFGC) is the term used for an individually adjusted standard for fundal height, estimated fetal weight and birthweight which takes into consideration maternal characteristics such as height, country of family origin, cigarette smoking and presence of diabetes.. Delphi technique. A technique used for the purpose of reaching an agreement on a particular issue, without the participants meeting or interacting directly. It involves sending participants a series of postal questionnaires asking them to record their views. After the first questionnaire, participants are asked to give further views in the light of the group feedback. The judgements of the participants are statistically aggregated. See also consensus methods.. Detection rate. 100% minus sensitivity.. Diagnosis. Confirmation of the presence of a disease/disorder.. Diagnostic study. A study to assess the effectiveness of a test or measurement in terms of its ability to accurately detect or exclude a specific disease.. Double-blind study. A study in which neither the subject (patient) nor the observer (investigator or clinician) is aware of which treatment or intervention the subject is receiving. The purpose of blinding is to protect against bias.. Evidence based. The process of systematically finding, appraising and using research findings as the basis for clinical decisions.. Evidence-based clinical practice. Evidence-based clinical practice involves making decisions about the care of individual patients based on the best research evidence available rather than basing decisions on personal opinions or common practice (which may not always be evidence based). Evidence-based clinical practice therefore involves integrating individual clinical expertise and patient preferences with the best available evidence from research.. Evidence level (EL). A code (eg. 1++, 1+) linked to an individual study or systematic review indicating where it fits in the hierarchy of evidence and how well it has adhered to recognised research principles.. Evidence table. A table summarising the results of a collection of studies which, taken together, represent the evidence supporting a particular recommendation or series of recommendations in a guideline.. Exclusion criteria. See Selection criteria.. Experimental study. A research study designed to test whether a treatment or intervention has an effect on the course or outcome of a condition or disease, where the conditions of testing are to some extent under the control of the investigator. Controlled clinical trials and randomised controlled trials are examples of experimental studies.. False positive rate. 100% minus specificity.. First contact. The initial appointment where the woman first meets a healthcare professional with a confirmed pregnancy. This appointment includes referral into the maternity care pathway and is an opportunity for information giving to ensure the woman is able to make informed decisions about her pregnancy care, including all antenatal screening and to raise awareness about health-related issues that are particularly relevant in early pregnancy.. Gold standard. A method, procedure or measurement that is widely accepted as being the best available.. Gravid. Pregnant.. Guideline. A systematically developed tool that describes aspects of a person’s condition and the care to be given. A good guideline makes recommendations based on best research evidence available, rather than opinion. It is used to assist clinician and patient decision making about appropriate health care for specific conditions.. xviii.

(21) Health economics. A field of conventional economics which examines the benefits of healthcare interventions (e.g. medicines) compared with their financial costs.. Health technology. Health technologies include medicines, medical devices, diagnostic techniques, surgical procedures, health promotion activities and other therapeutic interventions.. Heterogeneity. Or lack of homogeneity. The term is used in meta-analyses and systematic reviews when the results or estimates of effects of treatment from separate studies seem to be very different, in terms of the size of treatment effects, or even to the extent that some indicate beneficial and others suggest adverse treatment effects. Such results may occur as a result of differences between studies in terms of the patient populations, outcome measures, definition of variables or duration of follow up.. Hierarchy of evidence. An established hierarchy of study types, based on the degree of certainty that can be attributed to the conclusions that can be drawn from a well-conducted study. Wellconducted randomised controlled trials (RCTs) are at the top of this hierarchy.. Homogeneity. This means that the results of studies included in a systematic review or meta-analysis are similar and there is no evidence of heterogeneity. Results are usually regarded as homogeneous when differences between studies could reasonably be expected to occur by chance. See also consistency.. Inclusion criteria. See selection criteria.. Integrated test. A battery of screening tests used together to determine the risk of the unborn baby having Down’s syndrome. The tests are: a nuchal translucency ultrasound scan plus blood tests to measure levels of a beta human chorionic gonadotrophin (β-hCG)and pregnancy-associated plasma protein-A. These tests should be performed between 11 weeks 0 days and 13 weeks 6 days. This is then followed by a second battery of blood tests: alpha-fetoprotein, uE3 and inhibin A between 15 weeks 0 days and 20 weeks 0 days. The woman waits for results from the second set of tests before she is told her risk level.. Intention-to-treat analysis. An analysis of a clinical trial where particpants are analysed according to the group to which they are initially randomly allocated, regardless of whether or not they had dropped out of the study, fully received the intervention as intended or crossed over to an alternative intervention.. Intervention. Healthcare action intended to benefit the patient, e.g. drug treatment, surgical procedure, psychological therapy.. Likelihood ratio. See negative likelihood ratio and positive likelihood ratio.. Longitudinal study. A study of the same group of people at more than one point in time. (This type of study contrasts with a cross-sectional study, which observes a defined set of people at a single point in time.). Masking. See blinding.. Meta-analysis. Results from a collection of independent studies (investigating the same treatment) are pooled, using statistical techniques to synthesise their findings into a single estimate of a treatment effect. Where studies are not compatible, e.g. because of differences in the study populations or in the outcomes measured, it may be inappropriate or even misleading to statistically pool results in this way. See also systematic review and heterogeneity.. Multiparous. Having carried more than one pregnancy to a viable stage.. Negative likelihood ratio (LR–). The negative likelihood ratio describes the probability of having a negative test result in the diseased population compared with that of a non-diseased population and corresponds to the ratio of the false negative rate divided by the true negative rate ((1 – sensitivity)/specificity).. Negative predictive value (NPV). The proportion of people with a negative test result who do not have the disease (where not having the disease is indicated by the gold test being negative).. Nominal group technique. A technique used for the purpose of reaching an agreement on a particular issue. It uses a variety of postal and direct contact techniques, with individual judgements being aggregated statistically to derive the group judgement. See also consensus methods.. Non-experimental study. A study based on subjects selected on the basis of their availability, with no attempt having been made to avoid problems of bias.. Nulliparous. Having never given birth to a viable infant.. xix. 2008 update. Glossary of terms.

(22) 2008 update. Antenatal care. Number needed to treat (NNT). This measures the impact of a treatment or intervention. It states how many patients need to be treated with the treatment in question in order to prevent an event that would otherwise occur; e.g. if the NNT = 4, then four patients would have to be treated to prevent one bad outcome. The closer the NNT is to one, the better the treatment is. Analogous to the NNT is the number needed to harm (NNH), which is the number of patients that would need to receive a treatment to cause one additional adverse event. e.g. if the NNH = 4, then four patients would have to be treated for one bad outcome to occur.. Observational study. In research about diseases or treatments, this refers to a study in which nature is allowed to take its course. Changes or differences in one characteristic (e.g. whether or not people received a specific treatment or intervention) are studied in relation to changes or differences in other(s) (e.g. whether or not they died), without the intervention of the investigator. There is a greater risk of selection bias than in experimental studies.. Odds ratio (OR). Odds are a way of representing probability, especially familiar from betting. In recent years odds ratios have become widely used in reports of clinical studies. They provide an estimate (usually with a confidence interval) for the effect of a treatment. Odds are used to convey the idea of ‘risk’ and an odds ratio of one between two treatment groups would imply that the risks of an adverse outcome were the same in each group. For rare events the odds ratio and the relative risk (which uses actual risks and not odds) will be very similar. See also relative risk, risk ratio.. Parous. Having borne at least one viable offspring (usually more than 24 weeks of gestation).. Peer review. Review of a study, service or recommendations by those with similar interests and expertise to the people who produced the study findings or recommendations. Peer reviewers can include professional, patient and carer representatives.. Pilot study. A small-scale ‘test’ of the research instrument. For example, testing out (piloting) a new questionnaire with people who are similar to the population of the study, in order to highlight any problems or areas of concern, which can then be addressed before the fullscale study begins.. Placebo. Placebos are fake or inactive treatments received by participants allocated to the control group in a clinical trial, which are indistinguishable from the active treatments being given in the experimental group. They are used so that participants are ignorant of their treatment allocation in order to be able to quantify the effect of the experimental treatment over and above any placebo effect due to receiving care or attention.. Placebo effect. A beneficial (or adverse) effect produced by a placebo and not due to any property of the placebo itself.. Positive likelihood ratio (LR+). The positive likelihood ratio describes the probability of having a positive test result in the diseased population compared with that of a non-diseased population and corresponds to the ratio of the true positive rate divided by the false positive rate (sensitivity/(1−specificity)).. Positive predictive value (PPV). The proportion of people with a positive test result who have the condition (where having the condition is indicated by the gold standard test being positive).. Power. See statistical power.. Prospective study. A study in which people are entered into the research and then followed up over a period of time with future events recorded as they happen. This contrasts with studies that are retrospective.. P value. If a study is done to compare two treatments then the P value is the probability of obtaining the results of that study, or something more extreme, if there really was no difference between treatments. (The assumption that there really is no difference between treatments is called the ‘null hypothesis’.) Suppose the P value was 0.03. What this means is that, if there really was no difference between treatments, there would only be a 3% chance of getting the kind of results obtained. Since this chance seems quite low we should question the validity of the assumption that there really is no difference between treatments. We would conclude that there probably is a difference between treatments. By convention, where the value of P is below 0.05 (i.e. less than 5%) the result is seen as statistically significant. Where the value of P is 0.001 or less, the result is seen as highly significant. P values just tell us whether an effect can be regarded as statistically significant or not. In no way do they relate to how big the effect might be, for which we need the confidence interval.. xx.

(23) Qualitative research. Qualitative research is used to explore and understand people’s beliefs, experiences, attitudes, behaviour and interactions. It generates non-numerical data, e.g. a patient’s description of their pain rather than a measure of pain. In health care, qualitative techniques have been commonly used in research documenting the experience of chronic illness and in studies about the functioning of organisations. Qualitative research techniques such as focus groups and in-depth interviews have been used in one-off projects commissioned by guideline development groups to find out more about the views and experiences of patients and carers.. Quality-adjusted life years (QALYs). A measure of health outcome that looks at both length of life and quality of life. QALYs are calculated by estimating the years of life remaining for a person following a particular care pathway and weighting each year with a quality of life score (on a zero to one scale). One QALY is equal to 1 year of life in perfect health, or 2 years at 50% health, and so on.. Quantitative research. Research that generates numerical data or data that can be converted into numbers, for example clinical trials or the National Census, which counts people and households.. Random allocation or randomisation. A method that uses the play of chance to assign participants to comparison groups in a research study; for example, by using a random numbers table or a computer-generated random sequence. Random allocation implies that each individual (or each unit in the case of cluster randomisation) being entered into a study has the same chance of receiving each of the possible interventions.. Randomised controlled trial. A study to test a specific drug or other treatment in which people are randomly assigned to two (or more) groups: one (the experimental group) receiving the treatment that is being tested, and the other (the comparison or control group) receiving an alternative treatment, a placebo (dummy treatment) or no treatment. The two groups are followed up to compare differences in outcomes to see how effective the experimental treatment was. (Through randomisation, the groups should be similar in all aspects apart from the treatment they receive during the study.). Relative risk (RR). A summary measure which represents the ratio of the risk of a given event or outcome (e.g. an adverse reaction to the drug being tested) in one group of subjects compared with another group. When the ‘risk’ of the event is the same in the two groups the relative risk is 1. In a study comparing two treatments, a relative risk of 2 would indicate that patients receiving one of the treatments had twice the risk of an undesirable outcome than those receiving the other treatment. Relative risk is sometimes used as a synonym for risk ratio.. Reliability. Reliability refers to a method of measurement that consistently gives the same results. For example, someone who has a high score on one occasion tends to have a high score if measured on another occasion very soon afterwards. With physical assessments it is possible for different clinicians to make independent assessments in quick succession and if their assessments tend to agree then the method of assessment is said to be reliable.. Retrospective study. A retrospective study deals with the present and past and does not involve studying future events. This contrasts with studies that are prospective.. Risk ratio. Ratio of the risk of an undesirable event or outcome occurring in a group of patients receiving experimental treatment compared with a comparison (control) group. The term relative risk is sometimes used as a synonym of risk ratio.. Sample. A part of the study’s target population from which the subjects of the study will be recruited. If subjects are drawn in an unbiased way from a particular population, the results can be generalised from the sample to the population as a whole.. Screening. Screening is a public health service in which members of a defined population, who do not necessarily perceive they are at risk of, or are already affected by a disease or its complications, are asked a question or offered a test, to identify those individuals who are more likely to be helped than harmed by further tests or treatment to reduce the risk of a disease or its complications.. Selection criteria. Explicit standards used by guideline development groups to decide which studies should be included and excluded from consideration as potential sources of evidence.. Sensitivity. In diagnostic testing, sensitivity refers to the proportion of cases with the target condition correctly identified by the diagnostic test out of all the cases that have the target condition.. Specificity. In diagnostic testing, specificity refers to the proportion of cases without the target condition correctly identified by the diagnostic test out of all the cases that do not have the target condition.. xxi. 2008 update. Glossary of terms.

(24) Antenatal care. The ability of a study to demonstrate an association or causal relationship between two variables, given that an association exists. For example, 80% power in a clinical trial means that the study has a 80% chance of ending up with a P value of less than 5% in a statistical test (i.e. a statistically significant treatment effect) if there really was an important difference (e.g. 10% versus 5% mortality) between treatments. If the statistical power of a study is low, the study results will be questionable (the study might have been too small to detect any differences). By convention, 80% is an acceptable level of power. See also P value.. Study type. The kind of design used for a study. Randomised controlled trials, case–control studies and cohort studies are all examples of study types.. Systematic review. A review in which evidence from scientific studies has been identified, appraised and synthesised in a methodical way according to predetermined criteria. May or may not include a meta-analysis.. Technology appraisal. A technology appraisal, as undertaken by NICE, is the process of determining the clinical and cost-effectiveness of a health technology. NICE technology appraisals are designed to provide patients, health professionals and managers with an authoritative source of advice on new and exisiting health technologies.. Test. A procedure conducted to look for a pre-defined target of interest – either in terms of its presence/absence, or the amount/level contained in the body or a body fluid.. Validity. Assessment of how well a tool or instrument measures what it is intended to measure.. Variable. A measurement that can vary within a study, e.g. the age of participants. Variability is present when differences can be seen between different people or within the same person over time, with respect to any characteristic or feature that can be assessed or measured.. 2008 update. Statistical power. xxii.

(25) 1 Introduction 1.0. Introduction The original antenatal care guideline was published by NICE in 2003. Since then a number of important pieces of evidence have become available, particularly concerning gestational diabetes, haemoglobinopathy and ultrasound, so that the update was initiated. This update has also provided an opportunity to look at a number of aspects of antenatal care:. 1.1. 2008 update. • the development of a method to assess women for whom additional care is necessary (the ‘antenatal assessment tool’) • information giving to women • lifestyle: – vitamin D supplementation – alcohol consumption • screening for the baby: – use of ultrasound for gestational age assessment and screening for fetal abnormalities – methods for determining normal fetal growth – placenta praevia • screening for the mother: – haemoglobinopathy screening – gestational diabetes – pre-eclampsia and preterm labour – chlamydia.. Aim of the guideline The ethos of this guideline is that pregnancy is a normal physiological process and that, as such, any interventions offered should have known benefits and be acceptable to pregnant women. The guideline has been developed with the following aims: to offer information on best practice for baseline clinical care of all pregnancies and comprehensive information on the antenatal care of the healthy woman with an uncomplicated singleton pregnancy. It provides evidence-based information for clinicians and pregnant women to make decisions about appropriate treatment in specific circumstances. The guideline will complement the Children’s National Service Frameworks (England and Wales) (2004) which provides standards for service configuration, with emphasis on how care is delivered and by whom, including issues of ensuring equity of access to care for disadvantaged women and women’s views about service provision (For more information, see www.dh.gov.uk/en/Healthcare/NationalServiceFrameworks/ChildrenServices/ index.htm for England and www.wales.nhs.uk/ sites3/page.cfm?orgid=334&pid=934 for Wales). The guideline has also drawn on the evidence-based recommendations of the UK National Screening Committee (NSC). The Changing Childbirth report1 (1993) and Maternity Matters635 (2007) explicitly confirmed that women should be the focus of maternity care with an emphasis on providing choice, easy access and continuity of care. Care during pregnancy should enable a woman to make informed decisions, based on her needs, having discussed matters fully with the professionals involved. Reviews of women’s views on antenatal care, including a comprehensive national survey conducted by the National Perinatal Epidemiology Unit,994 suggest that key aspects of care valued by women are respect, competence, communication, support and convenience.2 Access to information and provision of care by the same small group of people are also key aspects of care that lend themselves to a pregnant woman feeling valued as an individual and more in control.3 Current models of antenatal care originated in the early decades of the 20th century. The pattern of visits recommended at that time (monthly until 30 weeks, then fortnightly to 36 weeks and then .

(26) Antenatal care. weekly until delivery) is still recognisable today. It has been said that antenatal care has escaped critical assessment.4 Both the individual components and composite package of antenatal care should conform to the criteria for a successful screening programme, namely that:. 2008 update. • the condition being screened for is an important health problem • the screening test (further diagnostic test and treatment) is safe and acceptable • the natural history of the condition is understood • early detection and treatment has benefit over later detection and treatment • the screening test is valid and reliable • treatments or interventions should be effective • there are adequate facilities for confirming the test results and resources for treatment • the objectives of screening justify the costs. A complete list of the NSC criteria for screening can be found in the NSC online library (www. nsc.nhs.uk/library/lib_ind.htm) under the title, The UK National Screening Committee’s criteria for appraising the viability, effectiveness and appropriateness of a screening programme.. 1.2. Areas outside the remit of the guideline The guideline will not produce standards for service configuration, which have been addressed by the Children’s National Service Frameworks (England and Wales), nor will it address quality standard issues (such as laboratory standards), which are addressed by the National Screening Committee.5 Although the guideline addresses screening for many of the complications of pregnancy, it does not include information on the investigation and appropriate ongoing management of these complications if they arise in pregnancy (for example, the management of pre-eclampsia, fetal anomalies and multiple pregnancies). Any aspect of intrapartum and postpartum care has not been included in this guideline. This includes preparation for birth and parenthood, risk factor assessment for intrapartum care, breastfeeding and postnatal depression. These topics will be addressed in future National Institute for Clinical Excellence (NICE) guidelines on intrapartum and postpartum care. In addition, preconception care is not covered in this guideline. The guideline offers recommendations on baseline clinical care for all pregnant women but it does not offer information on the additional care that some women will require. Pregnant women with the following conditions usually require care additional to that detailed in this guideline:. 2008 update. • cardiac disease, including hypertension • renal disease • hepatic disease • endocrine disorders or diabetes • psychiatric disorders (on medication) • haematological disorders, including sickle cell or thalassaemia, thromboembolic disease, autoimmune diseases such as antiphospholipid syndrome • epilepsy requiring anticonvulsant drugs • malignant disease • severe asthma • drug use such as heroin, cocaine (including crack cocaine) and ecstasy • HIV or hepatitis B virus (HBV) infected • cystic fibrosis • autoimmune disorders • obesity (body mass index, BMI, 35 kg/m² or more at first contact) or underweight (BMI less than 18 kg/m² at first contact) • women who may be at higher risk of developing complications e.g. women 40 years and older and women who smoke • women who are particularly vulnerable (e.g. women 18 years or younger) or who lack social support • family history of genetic disorder • multiple pregnancy .

(27) • women who have experienced any of the following in previous pregnancies: – recurrent miscarriage (three or more consecutive pregnancy losses) or a mid-trimester loss – severe pre-eclampsia, HELLP syndrome or eclampsia – rhesus isoimmunisation or other significant blood group antibodies – uterine surgery including caesarean section, myomectomy or cone biopsy – antenatal or postpartum haemorrhage on two occasions – retained placenta on two occasions – puerperal psychosis – grand multiparity (more than six pregnancies) – a stillbirth or neonatal death – a small-for-gestational-age (SGA) infant (less than fifth centile) – a large-for-gestational-age (LGA) infant (greater than 95th centile) – a baby weighing less than 2500 g or more than 4500 g – a baby with a congenital anomaly (structural or chromosomal).. 1.3. 2008 update. Introduction. For whom is the guideline intended? This guideline is of relevance to those who work in or use the National Health Service (NHS) in England and Wales:. A version of this guideline for pregnant women, their partners and the public is available from the NICE website (www.nice.org.uk/CG062publicinfo) or from NICE publications on 0845 003 7783 (quote reference number N1483).. 1.4. 2008. • professional groups who share in caring for pregnant women, such as obstetricians, midwives, radiographers, physiotherapists, anaesthetists, general practitioners, paediatricians, pharmacists and others • those with responsibilities for commissioning and planning maternity services, such as primary care trusts in England, Health Commission Wales, public health and trust managers • pregnant women.. Who has developed the guideline? The Guideline was developed by a multi-professional and lay working group, the Guideline Development Group (GDG), convened by the National Collaborating Centre for Women’s and Children’s Health (NCC-WCH). Membership included: • two service user representatives • two general practitioners • two midwives • two obstetricians • a radiographer • a neonatologist • a representative from the Confidential Enquiry into Maternal Deaths (CEMD). Staff from NCC-WCH provided methodological support for the guideline development process, undertook the systematic searches, retrieval and appraisal of the evidence and wrote successive drafts of the document.. 1.5. Who has developed the guideline update? The guideline update was developed by a multi-professional and lay working group, the Guideline Development Group (GDG), convened by the National Collaborating Centre for Women’s and Children’s Health (NCC-WCH). Membership included: • two service user representatives • two midwives . 2008 update. In accordance with the NICE guideline development process,6 all GDG members have made and updated any declarations of interest..

(28) Antenatal care. 2008 update. • two obstetricians • a general practitioner • an ultrasonographer • an MRC-funded public health research fellow. Staff from NCC-WCH provided methodological support for the guideline development process, undertook the systematic searches, retrieval and appraisal of the evidence and wrote successive drafts of the document. In accordance with the NICE guideline development process,6 all GDG members have made and updated any declarations of interest (Appendix A).. 1.6. Guideline methodology The development of the guideline was commissioned by the National Institute for Health and Clinical Excellence (NICE) and developed in accordance with the guideline development process outlined in The Guideline Development Process – Information for National Collaborating Centres and Guideline Development Groups, available from the NICE website (www.nice.org.uk).6. Update methodology The guideline update was developed in accordance with the NICE guideline development process outlined in the 2006 and 2007 editions of the guidelines manual.632,633 Table 1.1 summarises the key stages of the guideline development process and which version of the process was followed at each stage. Table 1.1 Stages in the NICE guideline development process and the versions followed at each stage. 2008 update. Stage Scoping the guideline (determining what the guideline would and would not cover) Preparing the work plan (agreeing timelines, milestones, Guideline Development Group constitution, etc.) Forming and running the Guideline Development Group Developing clinical questions Identifying the evidence Reviewing and grading the evidence Incorporating health economics Making group decisions and reaching consensus Linking guidance to other NICE guidance Creating guideline recommendations Developing clinical audit criteria Writing the guideline Validation (stakeholder consultation on the draft guideline) Declaration of interestsa a. 2006 version 2007 version       . .         . The process for declaring interests was extended in November 2006 to cover NCC-WCH staff and to include personal family interests.. Literature search strategy The aim of the literature review was to identify and synthesise relevant evidence within the published literature, in order to answer the specific clinical questions. Searches were performed using generic and specially developed filters, relevant MeSH (medical subject headings) terms and free-text terms. Details of all literature searches are available upon application to the NCC-WCH.. .

(29) Introduction. Guidelines by other development groups were searched for on the National Guidelines Clearinghouse database, the TRIP database and OMNI service on the Internet. The reference lists in these guidelines were checked against the searches to identify any missing evidence. Searches were carried out for each topic of interest. The Cochrane Database of Systematic Reviews, up to Issue 3, 2003, was searched to identify systematic reviews of randomised controlled trials, with or without meta-analyses and randomised controlled trials. The electronic database, MEDLINE (Ovid version for the period January 1966 to April 2003), EMBASE (Ovid version from January 1980 to April 2003), MIDIRS (Midwives Information and Resource Service), CINAHL (Cumulative Index to Nursing and Allied Health Literature), the British Nursing Index (BNI) and PsychInfo were also searched. The Database of Abstracts and Reviews of Effectiveness (DARE) was searched. Reference lists of nonsystematic review articles and studies obtained from the initial search were reviewed and journals in the RCOG library were hand-searched to identify articles not yet indexed. There was no systematic attempt to search the ‘grey literature’ (conferences, abstracts, theses and unpublished trials). A preliminary scrutiny of titles and abstracts was undertaken and full papers were obtained if they appeared to address the GDG’s question relevant to the topic. Following a critical review of the full version of the study, articles not relevant to the subject in question were excluded. Studies that did not report on relevant outcomes were also excluded. Submitted evidence from stakeholders was included where the evidence was relevant to the GDG clinical question and when it was either better or equivalent in quality to the research identified in the literature searches. The economic evaluation included a search of: • NHS Economic Evaluations Database (NHS EED) • Health Economic Evaluation Database (HEED) • Cochrane Database of Systematic Reviews, Issue 3, 2003 • MEDLINE January 1966 to April 2003 • EMBASE 1980 to April 2003. Relevant experts in the field were contacted for further information. The search strategies were designed to find any economic study related to specific antenatal screening programmes. Abstracts and database reviews of papers found were reviewed by the health economist and were discarded if they appeared not to contain any economic data or if the focus of the paper did not relate to the precise topic or question being considered (i.e. to screening strategy alternatives that were not relevant to this guideline). Relevant references in the bibliographies of reviewed papers were also identified and reviewed. These were assessed by the health economists against standard criteria.. Literature search strategy for the 2008 update. Systematic searches to answer the clinical questions formulated and agreed by the GDG were executed using the following databases via the ‘Ovid’ platform: Medline (1966 onwards), Embase (1980 onwards), Cumulative Index to Nursing and Allied Health Literature (1982 onwards) and PsycINFO (1967 onwards). The most recent search conducted for the three Cochrane databases (Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and the Database of Abstracts of Reviews of Effects) was during Quarter 1, 2007. Searches to identify economic studies were undertaken using the above databases, and the NHS Economic Evaluations Database (NHS EED). Search strategies combined relevant controlled vocabulary and natural language in an effort to balance sensitivity and specificity. Unless advised by the GDG, searches were not date specific. Language restrictions were not applied to searches. Both generic and specially developed methodological search filters were used appropriately.. . 2008 update. Relevant published evidence to inform the guideline development process and answer the clinical questions was identified by systematic search strategies. Additionally, stakeholder organisations were invited to submit evidence for consideration by the GDG provided it was relevant to the clinical questions and of equivalent or better quality than evidence identified by the search strategies..

(30) Antenatal care. 2008 update. There was no systematic attempt to search grey literature (conferences, abstracts, theses and unpublished trials). Hand searching of journals not indexed on the databases was not undertaken. Towards the end of the guideline development process searches were re-executed, thereby including evidence published and included in the databases up to 8 June 2007. Any evidence published after this date was not included. This date should be considered the starting point for searching for new evidence for future updates to this guideline. Further details of the search strategies, including the methodological filters employed, are available on an accompanying disc.. Clinical effectiveness For all the subject areas, evidence from the study designs least subject to sources of bias was included. Where possible, the highest levels of evidence were used, but all papers were reviewed using established guides (see below). Published systematic reviews or meta-analyses were used if available. For subject areas where neither was available, other appropriate experimental or observational studies were sought. Identified articles were assessed methodologically and the best available evidence was used to form and support the recommendations. The highest level of evidence was selected for each clinical question. Using the evidence-level structure shown in Table 1.2, the retrieved evidence was graded accordingly. Table 1.2 Structure of evidence levels Level 1a 1b 2a 2b 3 4. Definition Systematic review and meta-analysis of randomised controlled trials At least one randomised controlled trial At least one well-designed controlled study without randomisation At least one other type of well-designed quasi-experimental study Well-designed non-experimental descriptive studies, such as comparative studies, correlation studies or case studies Expert committee reports or opinions and/or clinical experience of respected authorities. Hierarchy of evidence The clinical question dictates the highest level of evidence that should be sought. For issues of therapy or treatment, the highest level of evidence is meta-analyses of randomised controlled trials or randomised controlled trials themselves. This would equate to a grade A recommendation. For issues of prognosis, a cohort study is the best level of evidence available. The best possible level of evidence would equate to a grade B recommendation. It should not be interpreted as an inferior grade of recommendation, as it represents the highest level of evidence attainable for that type of clinical question. For diagnostic tests, test evaluation studies examining the performance of the test were used if the efficacy of the test was required. Where an evaluation of the effectiveness of the test on management and outcome was required, evidence from randomised controlled trials or cohort studies was sought. All retrieved articles have been appraised methodologically using established guides. Where appropriate, if a systematic review, meta-analysis or randomised controlled trial existed in relation to a topic, studies of a weaker design were not sought. The evidence was synthesised using qualitative methods. These involved summarising the content of identified papers in the form of evidence tables and agreeing brief statements that accurately reflect the relevant evidence. Quantitative techniques (meta-analyses) were performed if appropriate and necessary.. .

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