1 University Department of Anaesthetics and Intensive Care, Queen Elizabeth Hospital, Edgbaston, Birmingham B15 2TH, UK 2 Department of Health, Wellington House, 133155 Waterloo Road, London SE1 8UG, UK 3 University Department of Obstetrics and Gynaecology, Liverpool Womens Hospital, Liverpool L69 3BX, UK
A copy of the full report of the Confidence Enquires into Maternal Deaths 19971999 can be obtained from the Royal College of Obstetricians and Gynaecologists bookshop (Tel: +44 (0) 207 7726275, Fax: +44 (0) 207 7245991), or from the online bookshop: www.rcog.org.uk
The sixteenth of the triennial audits of the Confidential Enquiries into Maternal Deaths (CEMD) was published in December 2001,1 and examined 378 cases. From 1952 until 1984, records of maternal mortality were produced separately for England and Wales, and Scotland. Since the 19851987 triennial report,2 maternal deaths from these three countries have been combined and also include Northern Ireland, becoming a United Kingdom (UK) report.
A maternal death is defined by the International Classification of Diseases: Manual of the International Statistical Classification of Diseases, Injuries and Causes of Death (ninth revision, ICD9) as the death of a woman while pregnant or within 42 days of termination of pregnancy from any cause related to or aggravated by pregnancy or its management, but not from accidental or incidental causes.3 A further revision4 recognized that improved life support means that people may survive beyond 42 days after an event precipitating death and hence late deaths between 42 days and 1 yr after abortion, miscarriage, or delivery are also included.
The broad aims of the CEMD are to assess the main causes of maternal death, identify any avoidable or substandard factors, and inform health care professionals of the findings. It hopes that its recommendations will reduce maternal mortality and morbidity. A complicating factor is that there is no way of knowing how many pregnancies occur (indeed a woman herself may not know she is, or has been, pregnant). Therefore, the surrogate marker of maternities is used to estimate pregnancy denominator data. A maternity is a pregnancy that results in a live birth at any gestation or a stillbirth occurring at or after 24 completed weeks gestation and is required to be registered by law. Therefore, the data are available, and should be accurate and consistent between successive reports.
How well have the aims to reduce maternal mortality and improve care been met? If we look at the death rates since the reports began, it is evident that they have. The overall maternal death rate in the 19521954 report5 was 69 deaths per 100 000 maternities (England and Wales) compared with this report where the rate is 11.4 deaths per 100 000 maternities (UK). How much the reduced mortality is due to other factors than those described in the CEMDsuch as better nutrition, medical advances, or pressures from other sourcesis of course not possible to delineate.
The most marked improvement occurred in the 1950s and 1960s and although the improvement has appeared to level off, there has been better case ascertainment since 1994. Furthermore, it is important to appreciate that other factors associated with increased mortality are occurring in the childbearing population. For example, older mothers make up a larger proportion of maternities. In 1975, 6% of mothers were over 35 yr; in 1995, 11% were in this age category,6 and in 2000, the proportion was 17%.7 There has also been a dramatic increase in the Caesarean section rate: the proportion of women delivered by this route doubled in the 1970s from 4% in 1970 to 9% in 1980, and in the year 2000 it was 21.3% in England.7 Older women are also more likely to be delivered by Caesarean section.7
The improvements seen in anaesthesia are similarly dramatic. Until 1981, there were between 30 and 50 deaths in each triennium ascribed directly to anaesthesia. In the 19821984 triennium this figure was 19 deaths; between 1985 and 1996 (spanning four triennia and 12 yr), there were also 19 deaths. The reductions in mortality are in large part due to the recommendations in previous reports supported by the Obstetric Anaesthetists Association and The Royal College of Anaesthetists.
The aim of the CEMD to disseminate its information is further enhanced this triennium by encouraging the publication of individual chapters in relevant specialist journals. The authors are grateful to the Editor-in-Chief of the British Journal of Anaesthesia for publishing the anaesthesia chapter in this issue.8 This allows those readers in the UK who are not members of the Obstetric Anaesthetists Association (whose UK members have received a copy of the report, another new initiative), and overseas readers to be aware of its findings and recommendations. The use of case vignettes is a popular feature of the chapters in the CEMD reports, making for easy reading and understanding of the clinical context. The chapter highlights the cases where anaesthesia was felt to be the direct cause of death: it is noteworthy that in two of these cases, death was ascribed to anaesthetics given after prolonged and complex treatment in intensive care. Without the skill displayed in their intensive care management, these patients may not have survived to require these anaesthetics. The first case of the chapter is of particular importance because the final insult was the hypotensive effect of oxytocin (Syntocinon), whose correct dose and pharmacological effects are apparently poorly recognized. Many lessons are to be learned from the other cases illustrated, in some of which anaesthetists were not actually involved, but should have been.
The importance of CEMD 19971999
Although all CEMD reports are important, the 19971999 report is possibly one of the most significant to have been published to date. For the first time, this report has been able to evaluate, more fully, other factors that may have played a part in the womans death. These findings are of great concern, showing the maternal mortality rate among the most disadvantaged groups of society was about 20 times higher than among women in the highest two social classes. Women from ethnic groups other than white were, on average, twice as likely to die than women in the white group. A large number of these women spoke little English. There was also a disproportionate number of deaths from the traditional travelling community (such as gypsies). Alarmingly, 12% of women whose deaths are included in the report self-declared to a health care worker during their pregnancy that they were subject to violence in the home.
Other factors associated with an increased risk of death include young women under 18 yr, increasing maternal age, and increasing parity. Many women were obese. There also appeared to be over-representation of women with multiple pregnancies and those who had undergone in vitro fertilization. Although all these findings should be regarded with care, because the very small numbers involved mean they cannot be proven with statistical rigour, they nevertheless provide a unique indicator of the impact that social exclusion may have on a womans reproductive health.
This report has also shown that the routine use of national guidelines can work. In this triennium, following the routine introduction and use of guidelines developed in part as a result of findings and recommendations from previous CEMD reports, there have been significant decreases in deaths from pulmonary embolism and sepsis following Caesarean section. In the very few cases where this occurred, guidelines do not appear to have been followed. Summaries of the major causes of direct maternal deaths for the years 19851999 are summarized in Figure 1.
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For the first time, the number of indirect deaths from medical conditions exacerbated by pregnancy are greater than deaths from conditions that directly arise from pregnancy. In part, this increase may be explained by the greater number of women with life-threatening medical conditions that are exacerbated by pregnancy, such as primary pulmonary hypertension and cystic fibrosis, choosing to become pregnant. Deaths from cardiac disease are the joint leading cause with thromboembolism of maternal death reported to this enquiry, as shown in Figure 2, and continuing deaths from other medical causes including conditions such as epilepsy and diabetes also underline the need for multidisciplinary antenatal care and plans for delivery.
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Although the chapter about deaths from psychiatric causes was only introduced for the first time in the 19941996 report,9 its great social importance is reinforced in this triennium. Although these deaths are not recognized as maternal deaths by the International Classification of Diseases, and thus not counted in the overall maternal mortality rate for other countries, in the UK psychiatric deaths indirectly related to pregnancy are considered to be indirect or late indirect maternal deaths. This means they receive the attention and recommendations they deserve in this report. However, as a consequence, they inflate the UK maternal death rate when compared with other countries. In this triennium, psychiatric factors were found to be the second most common reported cause of maternal death, being associated with 12% of maternal deaths, with suicide accounting for 10% of maternal deaths. If the unreported deaths from suicide in pregnant women obtained from the Office of National Statistics are taken into account, suicide is in fact the leading cause of maternal death overall. The risk of suicide is 1 per 100 000 maternities. The suicides in this group of women are characterized by their violent nature, rather than overdose with psychotropic medication.
The chapters relating to deaths from thromboembolism, hypertensive disorders, and haemorrhage are of direct relevance to anaesthetists. The welcome return of the Caesarean section chapter, after its absence in the 19941996 report,9 is also pertinent. The chapter on intensive care, first introduced in the 19911993 report,10 is of equal interest. The main findings from these chapters are highlighted here.
Thromboembolism
The reduction of deaths from thromboembolism from 48 deaths (19941996) to 35 deaths in this triennium is gratifying. Of the 17 postpartum deaths from pulmonary embolism, 10 followed vaginal delivery. The other seven postpartum deaths followed Caesarean section, but in three of these cases the operation had been performed in an attempt to save the baby after massive antepartum pulmonary embolism. The reduction in deaths from this cause has occurred despite more women being at risk of thrombosis because of the rising Caesarean section rate. This improvement is ascribed to adherence to Royal College of Obstetricians and Gynaecologists guidelines on thromboprophylaxis published in 1995,11 which have more recently been updated.12 The recommendation from the 19941996 report,9 is repeated with added emphasis; Wider use of thromboprophylaxis (not only after Caesarean section) and better investigation of classic symptoms (particularly in high risk women) are urgently recommended. The importance of risk factors, such as family history of thromboembolism, obesity, long-term immobilization, and varicose veins, is emphasized.
Hypertensive disorders
The largest single cause of death among those women with pre-eclampsia and eclampsia was intracranial haemorrhage, reflecting a failure of antihypertensive treatment. There were five deaths after definite or probable eclamptic fits. Magnesium sulphate is the anticonvulsant of choice in eclampsia,13 14 but its precise role in pre-eclampsia has yet to be established with clarity.15 Hopefully, the situation will be clearer when the results of the multinational Magpie trial are reported in 2002.16
The HELLP syndrome, first identified as an entity in 1982,17 where haemolysis, elevated liver enzymes, and low platelets complicate pre-eclampsia, was also responsible for five deaths in this triennium. The importance of anticipation of problems and multidisciplinary team working in this condition is emphasized.
Haemorrhage
The number of direct deaths due to haemorrhage has decreased from 9.2 per million maternities in 19881990, to 3.3 per million maternities. Of the seven deaths in this triennium due to antepartum and postpartum haemorrhage, three were due to placenta praevia, three to abruption of the placenta, and one to postpartum haemorrhage. A vignette illustrates the speed with which obstetric haemorrhage can become life-threatening where 60 units of blood were given in 2 h and 200 units given overall. This case emphasizes the need for women known to be at high risk of haemorrhage to be delivered at a hospital where blood and laboratory facilities, including haematological advice, are instantly available. Despite the caveats about the administration of Syntocinon earlier in this editorial, it is important to stress the need for effective oxytocic treatment where the need arises, as with atonic postpartum haemorrhage.
Caesarean section
One hundred and twenty women in the report were delivered by Caesarean section. The limitations of estimating fatality rates from Caesarean section are acknowledged. The data are observational and death is an amalgamation of the risk associated with the disorder for which surgery is indicated (such as pre-eclampsia or placenta praevia), and the risk associated with the procedure itself (including anaesthesia and perioperative care). Nevertheless, it is useful to note that if the risk of death from vaginal delivery is 1, the relative risk for all Caesarean sections is 4.9. The relative risk for elective Caesarean section is 2.3 compared with 12.0 when the Caesarean is performed because of immediate threat to the life of the mother or fetus. It is also pertinent that the relative risk of instrumental vaginal delivery is 3.1 compared with spontaneous vaginal delivery.
Intensive care
Over 31% of deaths were recorded as requiring intensive care. The reasons for admission ranged from a short period of attempted resuscitation to up to 90 days intensive care and organ support for patients with hypoxic encephalopathy or multiple organ failure. The ongoing and possibly increasing problem of lack of availability of intensive care beds, and the need for transfer to these facilities from isolated maternity units, is highlighted.
The future of CEMD
Responsibility for the CEMD was transferred to the National Institute for Clinical Excellence (NICE) in 2000. NICE is reviewing the most appropriate format for this and the other confidential enquiries (those into stillbirths and deaths in infancy (CESDI), perioperative deaths, and homicides and suicides). NICE has proposed that in 2003 the CEMD will merge with CESDI to form a new Maternal And Child Health Confidential Enquiry. This would benefit the CEMD, in terms of increased administrative support, as this enquiry has always been undertaken on an extremely modest budget, representing enormous value for money. This is in a large part because of the whole-hearted support of the profession, particularly the regional assessors who give of their free time to evaluate the individual cases. It is vital that the current feeling of ownership of the CEMD is retained. Although still going through the consultation exercise, it is possible that the future format could include comparisons of deaths with near misses. For this to be successful, much better information systems than are currently available will be needed. It is further hoped to include pregnancy-based fields in the Intensive Care National Audit Research Centre (ICNARC) data set. If this is achieved, it would help identify some of the near misses. But this is currently done voluntarily by the participating intensive care units and is not all-inclusive.
References
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2 Report on Confidential Enquiries into Maternal Deaths in the United Kingdom 19851987. Department of Health, Welsh Office, Scottish Home and Health Department, Department of Health and Social Security, Northern Ireland. London: HMSO, 1991
3 World Health Organization. International Classification of Diseases. Manual of the International Statistical Classification of Diseases, Injuries and Causes of Death. Ninth Revision, Vol. 1. Geneva: WHO, 1980
4 World Health Organization. International Statistical Classification of Diseases and Related Health Problems. Tenth Revision, Vol. 1. Geneva: WHO, 1992
5 Ministry of Health. Reports on Public Health and Medical Subjects No. 97. Report on Confidential Enquiries into Maternal Deaths in England and Wales 19521954. London: HMSO, 1957
6 Government Statistical Service. NHS Maternity Statistics, England: 19891990 to 19941995. London: HMSO, 1998
7 Thomas J, Paranjothy S. Royal College of Obstetricians and Gynaecologists. Clinical Effectiveness Support Unit. The National Sentinel Caesarean Section Audit Report. London: Royal College of Obstetricians and Gynaecologists, 2001
8 Thomas TA, Cooper GM. Maternal deaths form anaesthesia. An extract from Why Mothers Die 19971999, the Confidential Enquiries into Maternal Deaths in the United Kingdom. Br J Anaesth 2002; 89: 449508
9 Why Mothers Die. Report on Confidential Enquiries into Maternal Deaths in the United Kingdom 19941996. Department of Health, Welsh Office, Scottish Home and Health Department, Department of Health and Social Security, Northern Ireland. London: TSO, 1998
10 Report on Confidential Enquiries into maternal deaths in the United Kingdom 19911993. Department of Health, Welsh Office, Scottish Home and Health Department, Department of Health and Social Security, Northern Ireland. London: HMSO, 1996
11 Royal College of Obstetricians and Gynaecologists. Report of a Working Party on Prophylaxis Against Thromboembolism in Gynaecology and Obstetrics. London: Royal College of Obstetricians and Gynaecologists, 1995
12 Royal College of Obstetricians and Gynaecologists. Thromboembolic Disease in Pregnancy and the Puerperium: Acute Management. Guideline No. 28. London: Royal College of Obstetricians and Gynaecologists, 2001
13 Duley L, Henderson-Smart DJ. Magnesium sulphate versus diazepam for eclampsia. Cochrane Database Syst Rev 2001; Issue 2
14 Duley L, Henderson-Smart DJ. Magnesium sulphate versus phenytoin for eclampsia. Cochrane Database Syst Rev 2001; Issue 2
15 Duley L, Gulmezoglu AM, Henderson-Smart DJ. Anticonvulsants for women with pre-eclampsia. Cochrane Database Syst Rev 2001; Issue 2
17 Weiner L. Syndrome of hemolysis, elevated liver enzymes and low platelet count: a severe consequence of hypertension in pregnancy. Am J Obstetrics Gynecol 1982; 142: 15967