Trends in Perinatal Mortality in Scotland a Review Over 30 Years
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Trends in Perinatal Mortality in Scotland A review over 30 years Trends in Perinatal Mortality in Scotland - a review over 30 years Trends in Perinatal Mortality in Scotland - a review over 30 years Trends in Perinatal Mortality in Scotland A review over 30 years Information Services Division NHSScotland NHS Quality Improvement Scotland (NHS QIS) Reproductive Health Programme Edinburgh 2009 Trends in Perinatal Mortality in Scotland - a review over 30 years © Common Services Agency/Crown Copyright 2009 Brief extracts from this publication may be reproduced provided the source is fully acknowledged. Proposals for the reproduction of large extracts should be addressed to ISD Publications, Area 114a, South Gyle Square, 1 South Gyle Crescent, Edinburgh, EH12 9EB NHS Quality Improvement Scotland (NHS QIS) Reproductive Health Programme ISBN-10: 1-84134-020-0 ISBN-13: 978-1-84134-020-3 Information Services Publication enquiries ISD Customer Support Desk Gyle Square, 1 South Gyle Crescent Edinburgh EH12 9EB Tel 0131 275 7777 Email [email protected] or Leslie Marr Reproductive Health Programme Coordinator NHS Quality Improvement Scotland Elliot House 8-10 Hillside Crescent Edinburgh EH7 5EA Tel 0131 623 4710 Email [email protected] Typeset by ISD Scotland Publications Trends in Perinatal Mortality in Scotland - a review over 30 years CONTENTS Acknowledgements 2 Conventions 3 Definitions 3 1 Summary 4 Background, methods and aims 4 Key Findings 4 Summary of recommendations 4 2 Introduction and Methods 5 Comparisons with other European Countries 5 3 Total Births 9 4 Stillbirths 10 Stillbirth and maternal age 10 Stillbirth and deprivation 12 Antepartum stillbirths 17 Intrapartum stillbirths 18 Coding 19 Paediatric classification 22 5 Neonatal deaths 23 6 Multiple births 24 7 Deprivation 27 Smoking 31 8 Summary of Recommendations 32 9 Limitations 33 10 Conclusions 34 11 References 35 12 Obstetric and Paediatric Classification - Categories 36 1 Trends in Perinatal Mortality in Scotland - a review over 30 years Acknowledgements This report was produced by: Andrew Lyon, Chair of The Scottish Perinatal Morbidity and Mortality Review Advisory Group, NHS Quality Improvement Scotland Jim Chalmers, Head of Women and Children’s Health Information Programme, Information Services Division, NHS Scotland Etta Shanks, Maternity and Neonatal Team Leader, Information Services Division, NHS Scotland Christopher Lennox, Clinical Advisor, Reproductive Health Programme, NHS QIS Leslie Marr, Reproductive Health Programme Coordinator, NHS QIS Angus K McFadyen, Reader in Health Statistics, Glasgow Caledonian University Special thanks are also due to: The unit coordinators, risk managers, clinicians and staff through out NHS Scotland who contributed the data for this report. Members of The Scottish Perinatal Morbidity and Mortality Review Advisory Group, NHS Quality Improvement Scotland. Addendum 1. Page 11 changed chart title from 1985-2006 ti 1985/87-2005/07. 2. Page 23 changed chart title from 1985/87-2005/07 to 1985-2007. 3. Page 24 changed chart title from 1975-2006 to 1975-2007. 4. Page 35 added in reference - Sandra Bonellie, James Chalmers, Ron Gray, Ian Greer, Stephen Jarvis, Claire Williams. Centile charts for birthweight for gestational age for Scottish singleton births. BMC Pregnancy and Childbirth 2008, :5doi:10.1186/1471-2393-8-5: <http://www.biomedcentral.com/1471- 2393/8/5>. 2 Trends in Perinatal Mortality in Scotland - a review over 30 years Conventions The following symbols and abbreviations have been used: AP Antepartum GROS General Register Office (Scotland) IP Intrapartum IUGR Intrauterine growth restriction SGA Small for gestational age SB Stillbirth NND Neonatal death ENN Early neonatal death LNN Late neonatal death PNND Post-neonatal death Definitions Stillbirths - Section 56(1) of the Registration of Births, Deaths and Marriages (Scotland) Act 1965 defined a stillbirth as a child which had issued forth from its mother after the 28th week of pregnancy and which did not breathe or show any other sign of life. The Stillbirth (Definition) Act 1992, which came into effect on 1 October 1992, amended Section 56(1) of the 1965 Act (and other relevant UK legislation), replacing the reference to the 28th week with a reference to the 24th week. In the section on European comparisons, the fetal mortality rate is defined as the number of fetal losses at or after 22 completed weeks of gestation in a given year, expressed per 1000 live and stillbirths in the same year. Neonatal deaths refer to deaths in the first four weeks of life. Early neonatal deaths refer to deaths in the first week of life (0-6 days). Late neonatal deaths refer to deaths in weeks two to four of life (7-27 days). Post-neonatal deaths refer to deaths after the first four weeks but before the end of the first year. 'Optimum women' refer to women aged between 20 and 34 and from the two least deprived quintiles (depcat 1 or 2). Term - at or over 37 weeks gestation. Preterm - less than 37 weeks gestation. Rates Stillbirth rates are given as a proportion of total live and stillbirths. Neonatal, post-neonatal and infant death rates are given as a proportion of live births only. Fetal mortality rates are given as a proportion of total of live and stillbirths. 3 Trends in Perinatal Mortality in Scotland - a review over 30 years 1 SUMMARY Background, methods and aim Annual reports on perinatal mortality in Scotland have been produced since 1977 and include a classification relating to the obstetric event leading to death. Since 1987, a paediatric classification which summarises the clinico-pathological events in the fetus or baby has been included to complement the obstetric classification. This report reviews the data over a variety of time periods (from 33 years to 15 years, depending on the available dataset) and describes some of the changes since data collection started. The data is collected across Scotland and therefore represents changes in the whole population. The aim of this report is to explore whether routinely collected data can be used to highlight any areas of concern and to suggest areas for further monitoring, analysis and reporting. It does not attempt to engage in detailed statistical analysis. Key Findings Stillbirth rates have changed little for the past two decades, having declined markedly in the previous decade. Socio-economic deprivation remains one of the factors associated with poor perinatal outcome. Women aged between 25 and 34 years have the lowest stillbirth rates. There is a steady rise in the number of women over the age of 35 years having their first child. There is a suggestion that term stillbirths and intrapartum stillbirths (fetal deaths during labour) have risen slightly in the past decade. The rate of twins has almost doubled in the past thirty years. There has also been an increase in the rate of preterm deliveries and caesarean section for these births. Summary of recommendations Reviewing population data over longer periods of time can show trends which may not be obvious when comparing single years. Areas of importance which can be investigated in more detail are highlighted in this review and should form the basis of subsequent reports. Comparisons with other European countries are important. Scotland should continue to contribute to international projects and assess areas of good practice which may be transferrable to the Scottish context. Current coding systems can no longer be used for meaningful surveillance of cause of perinatal death. In particular too many stillbirths are being classified as ‘unexplained’. There is a need to review the coding categories to include more extensive information available from post mortem and placental analysis. It is important to keep to a standardised coding scheme that will allow comparisons with other countries. Work is therefore needed to expand and validate improved systems of coding. Neonatal intensive care has had an impact on neonatal mortality rates but stillbirth rates are not continuing to fall. There has been a rise in stillbirth rates of term babies and a possible increase in intrapartum deaths. These are important preliminary findings and these data need further, and more detailed, analysis. Smoking is still more prevalent in the more deprived groups. There needs to be improved recording of smoking status. There have been recent publications on deprivation and pregnancy outcome. This work must be built upon. This must be more than an academic exercise and, where possible, changes in practice should be implemented and the impact assessed. 4 Trends in Perinatal Mortality in Scotland - a review over 30 years 2 INTRODUCTION AND METHODS Annual reports on perinatal mortality in Scotland have been produced since 1977 and include a classification relating to the obstetric event leading to death. Since 1987, a paediatric classification which summarises the clinico-pathological events in the fetus or baby has been included to complement the obstetric classification. This report reviews the data over a variety of time periods (from 33 years to 15 years, depending on the available dataset) and describes some of the changes since data collection started. The data is collected across Scotland and therefore represents changes in the whole population. The aim of this report is to explore whether routinely collected data can be used to highlight any areas of concern and to suggest areas for further monitoring, analysis and reporting. It does not attempt to engage in detailed statistical analysis. Mortality