Understanding our advice ~ February Routine ultrasound scanning before 24 weeks of pregnancy

Transcription

1 Understanding our advice ~ February 2004 Routine ultrasound scanning before 24 weeks of pregnancy

2 Routine ultrasound scanning before 24 weeks of pregnancy Purpose of this document NHS Quality Improvement Scotland (NHS QIS) has issued Advice to NHSScotland on the use of routine ultrasound scanning before 24 weeks of pregnancy. The Advice considers clinical and cost effectiveness, and organisation of services in Scotland. We have advised NHSScotland that each pregnant woman in Scotland should be offered an ultrasound scan in both the first and second trimesters of pregnancy. This brochure has been produced to explain our Advice on routine ultrasound scanning to people who do not have specialist knowledge in this area. It explains what the Advice means for women who have undergone, or may have to undergo, ultrasound scanning, how we formed the Advice, and what values we applied to the evidence about ultrasound scanning. The full evidence is discussed in detail in Health Technology Assessment 5: Routine ultrasound scanning before 24 weeks of pregnancy. The words in bold are explained in the Glossary at the end of this document. 1

3 What is ultrasound scanning? Ultrasound scanning uses high frequency sound waves to create a picture of the fetus during pregnancy. Scans provide information about the size of the fetus, the date the baby is due, and its development. Scans can also identify multiple pregnancies, for example twins. In the first trimester ultrasound measurements can be combined with the results of a blood test from the mother (called a serum screen). This measurement can be used to identify the risk of a baby having a disorder such as Down s syndrome. Ultrasound scanning in the second trimester can detect a number of serious problems including heart defects and spina bifida. Ultrasound scans will not pick up every problem. 2

4 Routine ultrasound scanning before 24 weeks of pregnancy Service in Scotland Ultrasound scanning is part of routine antenatal care in Scotland and each year over pregnant women are offered scans. Practice varies throughout the country, however, and ultrasound scanning is provided in different ways at different hospitals. Women are being offered ultrasound at different stages of pregnancy, and undergo different types of tests to assess the potential risk of conditions like Down s syndrome and spina bifida. Most women in Scotland are currently offered only one routine scan, usually during the first trimester. We have looked at the benefits and risks of using ultrasound scanning in the first 24 weeks of pregnancy and recommend that all pregnant women should be offered two routine scans. The first scan should be offered in the first trimester to determine the duration of pregnancy (gestational age) and identify potential problems with development of the fetus. Women should also be offered a screening test to identify the risk of Down s syndrome where ultrasound measurements will be taken (known as nuchal translucency measurement) and combined with the results of a blood test from the mother. This test needs to be carried out between 10 and 13 weeks of pregnancy. A follow-up test will be offered to a woman if she is found to have a higher chance of having a baby with Down s syndrome. There is a small risk that a woman may have a miscarriage as a result of these follow-up tests. The second ultrasound scan, called an anomaly scan, should be offered in the second trimester at between 18 and 22 weeks to identify certain fetal defects. 3

5 We have advised that pregnant women should be told exactly what ultrasound can and cannot detect so they can make an informed decision about whether or not to have ultrasound scanning. We have also advised that they should be provided with appropriate written information and given the opportunity to discuss issues or questions they may have before their first scan. Pregnant women are not required to have these scans and can choose to take part in some, all or none of the scanning programme. Those who decide to take part will be asked to provide written consent for some tests. Our advice should ensure that all pregnant women are offered a scanning and screening service that is: properly explained to them and only done with their informed consent as safe as possible for them and their babies as accurate as possible, while ensuring the least number of follow-up tests provided consistently throughout Scotland based on the latest evidence. 4

6 Routine ultrasound scanning before 24 weeks of pregnancy How we formed our Advice We used an internationally recognised process called Health Technology Assessment to form our Advice. The assessment took account of the social, ethical, medical and economic implications of routine ultrasound scanning before 24 weeks of pregnancy. It brought together: scientific evidence e.g. articles published in medical or scientific journals (journal articles) + expertise of health professionals + needs and preferences of pregnant women while considering the way NHSScotland is organised and how pregnant women are currently managed. We worked with a group of doctors, obstetricians, sonographers, midwives, nurses and pregnant women to look at all the evidence. The evidence was recorded in a consultation report. Comments received during consultation were published on the web and taken account of in our scientific document, the Health Technology Assessment Report, and our Advice to the health service in Scotland. 5

7 Evidence used We gathered evidence from around the world. We use the word evidence to include information collected from a variety of sources, and we use different types of evidence to answer different types of questions. For example: Issues for pregnant women What information needs do pregnant women have? Do they understand what the findings of a scan mean? Evidence came from journal articles and discussion groups with pregnant women. Clinical effectiveness What is the most clinically effective use of ultrasound scanning? When should pregnant women undergo a scan? Evidence came from journal articles, studies and manufacturers. Costs and benefits How much does ultrasound scanning equipment cost? What savings can be made from the earlier diagnosis it can provide and what are the benefits e.g. the reduced need for further invasive tests? Evidence came from studies we made on costs and savings, and information about clinical effectiveness. 6

8 Routine ultrasound scanning before 24 weeks of pregnancy Organisational issues What ultrasound scanning services are currently provided in Scotland? Do staff who provide ultrasound scanning have the appropriate training? Evidence came from studies and a national survey we undertook. The following diagram is an example of how all four types of evidence came together to help form our Advice. Cost and Benefits Introducing two ultrasound scans for all pregnant women increases costs but a nuchal translucency scan may reduce the need for follow-up tests and a second trimester scan can identify defects. ; Clincal Effectiveness Ultrasound scanning can accurately estimate date of delivery and allows early diagnosis of multiple pregnancies. It is also an effective method of identifying potential problems during pregnancy. For example, a nuchal translucency scan, combined with a blood test, can identify a risk of Down s syndrome ; Advice All pregnant women in Scotland should be offered both a first and second trimester scan. Appropriate written information should be provided to women and an opportunity given to discuss ultrasound scanning with a health professional prior to the first scan. ; Organisational Issues Ultrasound scanning should be performed by formally trained staff. ; Issues for Pregnant Women Ultrasound scanning reduces anxiety and early screening provides reassurance for the majority of pregnant women about their baby s health. 7

9 Sources of support and information If you, or your partner is due to undergo an ultrasound scan then you can discuss this Advice with your doctor or midwife. Further information about pregnancy and childbirth is available from the National Childbirth Trust ( tel The NHS QIS Advice to NHS Scotland, Health Technology Assessment Advice 5: Routine ultrasound scanning before 24 weeks of pregnancy and full scientific report, Health Technology Assessment Report 5: Routine ultrasound scanning before 24 weeks of pregnancy are available from NHS QIS or its website, 8

10 Routine ultrasound scanning before 24 weeks of pregnancy Glossary Advice Evidence-based recommendations made by NHS QIS about any aspect of healthcare including medicines, devices, clinical procedures, and healthcare settings. NHS Boards and health professionals are expected to take account of NHS QIS Advice when making decisions about services for patients. Clinical effectiveness The evaluation of benefit against risk in a standard clinical Down s syndrome Health technology setting using outcomes of importance to the patient. A lifelong disorder, which exists before birth, where the baby has an extra chromosome. An intervention used to promote health; prevent, diagnose or treat disease; or provide rehabilitation or long-term care. This includes medicines, devices, clinical procedures Fetus and healthcare settings. The unborn baby from the end of the eighth week after conception (when the major structures have formed) until birth. NHSScotland The National Health Service in Scotland. Nuchal translucency A measurement of the space between the skin and the bone in the fetal neck (taken at 10 to 13 weeks of the Obstetrician Serum screening pregnancy). A doctor who specialises in the care of pregnant women and delivery of babies. Measurement of markers present in the blood to give an estimate of the risk of potential abnormalities. 9

11 Sonographer Spina bifida Trimester A health professional who carries out ultrasound scans. A birth defect of the spinal column where part of the spinal cord is exposed. The nine months of pregnancy is traditionally divided into three trimesters: distinct periods of roughly three months in which different phases of development take place. 10

12 Routine ultrasound scanning before 24 weeks of pregnancy NHS Quality Improvement Scotland (NHS QIS) Our role is to improve the quality of healthcare in Scotland. We provide clear, authoritative advice on effective clinical practice, set national standards and monitor and publish reports on performance. We also advise on health interventions that are value for money, commission clinical guidelines and support the implementation of clinical governance. To advise on value for money, we must balance how well a treatment works with how much it costs. 11

13 Feedback Understanding our Advice aims to explain the work of NHS QIS in a way that everyone can understand. We would warmly welcome feedback on this brochure. For example, have we clearly explained our Advice on routine ultrasound scanning before 24 weeks of pregnancy, and do you have any questions that that were not answered here? Please give feedback to Rob MacPhail, Communications Officer, NHS Quality Improvement Scotland, Delta House, 50 West Nile Street, Glasgow G1 2NP, tel , rob.macphail@nhshealthquality.org 12

14 Routine ultrasound scanning before 24 weeks of pregnancy

15 NHS Quality Improvement Scotland, February 2004 ISBN First published February 2004 NHS Quality Improvement Scotland consents to the photocopying, electronic reproduction by uploading or downloading from the website, retransmission, or other copying of this document for the purpose of implementation in NHSScotland and educational and not for profit purposes. No reproduction by or for commercial organisations is permitted without the express written permission of NHS Quality Improvement Scotland.

16 This document can be viewed on the NHS QIS website. It is also available, on request, from NHS QIS in the following formats: Electronic Audio cassette Large print NHS Quality Improvement Scotland Glasgow Office ~ Delta House 50 West Nile Street Glasgow G1 2NP Tel Edinburgh Office ~ Elliott House 8-10 Hillside Crescent Edinburgh EH7 5EA Tel comments@nhshealthquality.org This document is produced from elemental chlorine-free material and is sourced from sustainable forests