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Clinical governance Increased risk of maternal death among ethnic minority women in the UK Authors Charles Anawo Ameh / Nynke van den Broek
Key content: • The most recent CEMACH report indicates that the UK maternal mortality rate has not fallen in recent years. • This was attributed, in part, to increasing numbers of deaths amongst immigrant women. • It is likely that newly-arrived refugees are affected most.
Learning objectives: • To be able to identify the factors contributing to the increased maternal mortality and morbidity. • To review the published evidence for effectiveness of interventions. • To identify appropriate research groups and organisations.
Ethical issues: • There is evidence to suggest that the care given to women from ethnic minority backgrounds, especially asylum seekers and newly-arrived refugees, is substandard. Keywords access to care / ethnic minority women / maternity services / refugees / travellers Please cite this article as: Ameh CA, van den Broek N. Increased risk of maternal death among ethnic minority women in the UK . The Obstetrician & Gynaecologist 2008;10:177–182.
Author details Charles Anawo Ameh DRH FWACS (Obs & Gyn) Sexual and Reproductive Health Technical Advisor Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
Nynke van den Broek PhD DTM & H FRCOG Senior Clinical Lecturer in Sexual and Reproductive Health Liverpool School of Tropical Medicine, UK Email:
[email protected] (corresponding author)
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Introduction There are over 536 000 maternal deaths worldwide each year,1 99% of which occur in the developing world. The estimated maternal mortality ratios for resource-poor countries show a wide disparity with those of the developed world (Table 1). The maternal mortality ratio for the UK is 12/100 000 live births.2 The sixth report2 from the Confidential Enquiry into Maternal and Child Health (CEMACH) (2000–2002) identified several risk factors associated with maternal deaths occurring in the UK. One of these was ethnicity. It was observed that the risk of dying in pregnancy for black women was seven times higher than for their white, Britishborn counterparts. Travellers and newly-arrived refugees were also observed to be at significantly increased risk. The factors found to be associated with the increased mortality among black and ethnic minority women included domestic violence, communication problems, refugee and recent immigration status, poor access to care and substandard care provision.2,3 In the most recent CEMACH report4 (2003–2005) it was noted that the UK maternal mortality rate had not fallen in recent years and this was attributed in part to increasing numbers of deaths amongst immigrant women. The numbers of births to women born outside the UK has increased. For this paper a review was undertaken of literature on maternal health and access to maternity services for black and ethnic minority women in the UK.
Search methods All electronic databases and relevant websites were searched. One hundred and sixty publications were identified, of which 34 were relevant to this review.
Terminology Most peer reviewed publications use the term ‘ethnic minority groups’ but there is a confusing array of definitions used in the literature (Table 2). Table 1
Maternal deaths per 100 000 live births
Maternal mortality estimates (United Nations, 2000)1
Region
Table 2
Terminology
Description
Terminology used to describe ethnic origin2,5-7
Ethnic minority groups
Ethnic groups other than white British women Groups other than white British Women born outside the UK Women who do not speak English Includes refugees, asylum seekers and recently-arrived women Includes gypsy population and population with no fixed abode
Developed countries Resource-poor/developing countries Africa Asia
Non-white groups Immigrant women Non-English speaking women Migrant women
Travellers
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20 440 830 330
Questions concerning ethnic origin were included in the 1991 and 2001 UK population censuses. In 2001, 10.1% of the UK female population (15–44 years) were reported as belonging to a ‘non-white group’.5 A mother’s country of birth is recorded at the time of birth registration and is assumed to be a proxy for the determination of ethnicity. This is a measure of migrant status and can lead to inaccurate ascription of ethnicity; for example, a Pakistani woman born in South Africa and having her baby in the UK will be assumed to be of black African ethnic origin. Such a method of categorisation will also lead to the non-identification of many women of black and ethnic minority descent. Ethnic minority women born in the UK (and their babies) are currently ‘invisible’ in birth and death registration statistics, as ethnic origin is not recorded.3,5,6 Mothers’self-reported ethnic origin has been recorded in the Hospitals Episode Statistics for England since 1995 and ethnic origin has been included in maternal death notification forms since 1994.3 The Hospitals Episode Statistics had 67% coverage for the period 2000–2002. In the sixth CEMACH report,2 analysis of maternal deaths by ethnic group was based on this Hospitals Episode Statistics classification as, although it was shown to be incomplete, it gave the best estimate of maternal death rates by ethnic group. Similarly, data used for the fifth report3 was less accurate because the Office for National Statistics codes for black African, black Caribbean, black other and black mixed were grouped together and the data were often incomplete. In its sixth report2 CEMACH advised caution when interpreting the findings on ethnicity and maternal risk of death because of the small numbers involved as well as the problem of coding difficulties.
Ethnic minority and obstetric risk No increase in any specific cause of maternal death has so far been identified.2,3 All seven publications that addressed this issue were retrospective studies with large sample sizes that controlled for important confounding factors and compared ethnic minority women to white Britishborn women. The majority of this research comes from areas with high populations of ethnic minorities such as East London and Leeds.5–8 In an analysis of maternal deaths in England and Wales between 1970 and 1985,9 an increased risk of death from all major causes was reported for women born in West Africa (relative risk [RR] 10.3, 95% CI 8.0–13.2) and the Caribbean (RR 4.6, CI 3.8–5.7). An increased incidence of obstetric
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complications and/or differences in the care given to ethnic minority women (‘immigrant groups’) may have accounted for this. This study used country of birth to define ethnic origin, so it is likely that white women born in Africa were included, while black Caribbean or Asian women born in the UK were excluded. Ibison7 also carried out a retrospective study to investigate the relationship between ethnicity and mode of delivery in low-risk primiparous women over a 10-year period at three London hospitals. There was a significantly elevated risk of operative delivery amongst ethnic minority mothers after adjusting for important confounding factors (healthcare provider and insurance status). The increase in risk was highest in black Africans and lowest amongst Indians and Pakistanis. This study had a large sample size (n27 667) and included over 95% of births for the three districts studied. It relied on an observer-assigned (not self-assigned) categorisation of ethnicity. Similarly, the National Sentinel Caesarean Section Audit in England10 found a 60% increased risk of caesarean section for black African women and 19% increased risk for black Caribbean women. This latter study did not adjust for antenatal care attendance, induction of labour, complications of pregnancy and type of care provider. In both studies the most common indication for caesarean section was fetal distress; however, details of how the diagnosis of fetal distress was made were not specified. In contrast,Versi et al.6 found no increased adverse obstetric outcome amongst Bangladeshi women compared to white women in East London (n16 718: 6460 [45.4%] Bangladeshi, 7592 [38.6%] white women and 2666 [16%] women of other ethnic minority groups). Two case control studies11,12 comparing obstetric outcome for white and Somali women (n61 in each group) and ethnic Albanian women from Kosovo (n69 in each group) did not find an increase in adverse obstetric complications. Female genital mutilation has been linked to poor management during pregnancy and labour in Somali women.13 This finding, however, was not confirmed by Yoong et al.12 The relative risk of death among all groups of women appears to be primarily related to their health-seeking behaviour, with women who did not access care, regardless of ethnic background, being most at risk.2
Access to care, antenatal clinic attendance and communication A disproportionate number of women from nonwhite groups whose deaths were reported in the last two CEMACH reports were recorded as having
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been poor antenatal care attenders—more than 50% of them had found it difficult to book or to attend clinic at the appropriate time.2 Six papers specifically address the issue of antenatal care attendance. One was a systematic review by Rowe and Garcia,14 the others were research papers.15–19 Four studies15–19 reported that women of Asian origin were more likely to book late for antenatal care compared with white British women. Although individual studies report differences in attendance and time of booking for ethnic minority women, the systematic review by Rowe and Garcia did not confirm social and ethnic inequality in antenatal care attendance. One study19 surveyed health professionals’ views about change in the provision and organisation of antenatal care. Most health professionals wanted to see individualised visit schedules and favoured a minimum total number of health professionals supervising each individual pregnancy. Most refugees are from ethnic minority groups. They generally face the same problems as recent migrants, including lack of access to health services, communication problems, lack of information about available maternal services20 and late booking for antenatal care.21,22 Inadequate translation services for non-English speaking women is a recurring problem. In the sixth CEMACH report,2 ten out of 14 recently arrived women in the UK who died were classified as refugees or asylum seekers, more than half of whom could not speak English. Translation services were not readily available and it is documented that in some instances relatives, including children, were used as interpreters.2 This was similar to Hayes’23 findings when she examined access to midwifery care and, in particular, availability and effectiveness of translation services for ethnic minority women in 22 health districts in the West Midlands. Interpreting services were not always available and women were asked to bring someone along to provide this service, including children. Hayes noted that having bilingual staff was useful in overcoming communication problems. Information given to women from ethnic minority groups was not as good as that given to their white counterparts. This was primarily a result of the fact that most written information was available only in English. Lack of good and sensitive communication between healthcare providers and women from ethnic minority groups or immigrant status has been documented and is known to contribute to poor access to and uptake of services.21,24 Communication failure between health professionals themselves can also contribute to poor uptake of some services; for example, failure 179
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to screen ethnic minority women for haemoglobinopathies.25
Quality and experience of maternity care It has been suggested that the increased risk of maternal death in black and ethnic minority women is associated with the quality of care received and that this is related to the institutional organisation of care. Substandard care was reported in over 50% of maternal deaths reported in the sixth CEMACH report.2 In the fifth CEMACH report, 28% of black and ethnic minority women, compared with 20% of white women, were reported to have received substandard care.3 Possible reasons for substandard care include poor communication skills, institutional dysfunction or lack of concern for less articulate women from poor social circumstances.2 While this can be difficult to substantiate, it does raise questions about the way women from ethnic minorities are cared for within the healthcare system when they do access it. In addition, it has been suggested that women of ethnic minority groups and refugees and/or travellers experience a greater dissonance between expectations and experience of maternity care compared with indigenous white women.24 Among women from ethnic minority background or immigrant status, further work is needed to document the experiences and expectations of care during pregnancy and childbirth in more depth. Continuity of carer (i.e. having a minimal number of different care givers during pregnancy, labour and the postpartum period) and trust in the care giver are highly valued.24,25 Healthcare providers themselves prefer more individualised antenatal care visits and continuity of carer for antenatal care services.26 The Maternity Alliance27 reported on a group of asylum seekers’ maternity experiences. About half of the women said they had experienced neglect, Box 1
Health interventions for ethnic minority women8,23,33–37
Effective or promising interventions
disrespect and racism when accessing maternity services and that poor or insufficient information had been given about which services were available to them. Interpreters were generally provided except during antenatal classes, which meant that many asylum seekers could not attend them. One of the recommendations of the Independent Inquiry into Inequalities in Health28 was the establishment of mechanisms to monitor inequality in health and to evaluate the effectiveness of measures taken to reduce this. High priority should be given to policies aimed at improving health inequalities in women of childbearing age, expectant mothers and young children.
Maternity services for travellers and obstetric outcome Two publications specifically addressed the issue of maternity services for travellers and concluded that obstetric and neonatal outcomes are poor among the travelling communities in the UK.29,30 The groups of particular concern are women who have recently arrived, in or after the second trimester of pregnancy, and who have no or minimal contact with maternity services. The problems described are broadly similar to those of women from ethnic minority groups as outlined above. A third publication related to the health of the travelling communities in general (not specifically pregnant women) found that travellers have significantly poorer health status than other UK resident, English-speaking ethnic minorities or economically disadvantaged white UK residents.31
Health intervention strategies for ethnic minority women D’Souza and Garcia20 carried out a review of studies on interventions to improve services for disadvantaged women. Box 1 lists some of the interventions that address the factors identified above. Key research groups with a focus on maternal health of ethnic minority women were identified from the literature and websites (Box 2). It is interesting to note that involving women from
Health advocacy for non-English speaking women Effective in increasing the length of antenatal stay (reducing antenatal care dropout rate) and lowering the rates of induction of labour and elective caesarean section Link and bilingual workers Increases Asian women’s satisfaction with services and may increase their knowledge of health services and healthy practices, particularly breastfeeding Prepregnancy defibulation for female genital mutilation Has the potential to reduce the risk of haemorrhage and severe pain during childbirth Training of lay women and multilingual pharmacists May result in increase in the uptake of health education messages
Interventions that have not been found to be effective
Health advocacy Unlikely to improve late booking, nonattendance at antenatal clinics and rates of low birthweight Link worker services Unlikely to improve the time of booking, gestational age at delivery and rates of low birthweight
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Organisation and website address
Description of research
Medical Research Council Social and Public Health Sciences Unit, Glasgow www.sphsu.mrc.ac.uk/programmes_home.php
Monitoring inequalities in the outcome of pregnancy Investigating maternity and postnatal care needs amongst UK-born ethnic minorities: perceptions from mothers, fathers and healthcare providers
The Centre for Ethnicity and Health, University of Central Lancashire www.uclan.ac.uk/facs/health/ethnicity/research/index.htm
Quality care to black and minority ethnic elders in health and social care across ethnic groups internationally
Department of Health and Social Care ‘Race’, ethnicity, and welfare research group, Royal Holloway University of London www.rhul.ac.uk/Health-and-SocialCare/Research/ ResearchGroup2_Racepublications.html
‘Young mothers and the care system: contextualising risk and vulnerability’; ‘Black African children and the child protection system’, British Journal of Social Work Race, ethnicity and parenting: understanding the impact of context, childRIGHT
The Centre for Research in Ethnic Relations, University of Warwick www.warwick.ac.uk/fac/soc/CRER_RC/
Experiences of people from ethnic minority groups in the UK and Western Europe
National Perinatal Epidemiology Unit, University of Oxford www.npeu.ox.ac.uk/
The study of socioeconomic and health conditions of ethnic minority families from the Millennium Cohort Study Barriers to care for low-income childbearing women
Research Centre forTranscultural Studies in Health, Middlesex University www.mdx.ac.uk/www/rctsh/
The EMBRACE UK Study: investigating and describing the health and social care needs of Ethiopian refugees and asylum seekers living in London
City University London www.city.ac.uk/sonm/research
Investigating maternity and postnatal care needs amongst UK-born ethnic minorities: perceptions from mothers, fathers and healthcare providers
Women’s Health and Family Services, London www.whfs.org.uk
Provides health advocacy, advice and support to women and their families from the Bengali, Chinese, Somali and Vietnamese communities Commissioned Born in UK project, which is being researched at City University London
Maternity Alliance, London www.maternityalliance.org.uk (This site is going to be launched in 2008)
Several research publications on maternal health in refugees and asylum seekers As Good as Your Word: a guide for setting up and managing interpreting and translating services and giving guidance on developing a policy on language and communication
ethnic minority groups in developing research questionnaires and adapting screening instruments can improve the acceptability and reliability of such studies.32 Some of the organisations that provide services, including advocacy, link worker and interpreting services, as well as clinics set up specifically for ethnic minority women, have not been included in Box 2. This is because they are not directly involved in research and/or there is no immediate access to reports evaluating the effects of such work. It is beyond the remit of this review to list all of them.
Conclusion Many of the factors associated with an increased risk of death among black and ethnic minority group women have been the subject of research in the last decade. Most of this was carried out amongst Asian (Pakistani, Bangladeshi and Indian) and Somali women. There is limited research on maternity services specifically for black and ethnic minority women born in the UK. Most studies on obstetric outcome are retrospective and pertain to data collected more than 15 years ago. Studies on quality of care or maternity experiences of ethnic minority women are generally qualitative and have very small sample sizes. Despite limited specific and good-quality evidence there are consistent messages that suggest that black © 2008 Royal College of Obstetricians and Gynaecologists
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Box 2
Organisations involved in research into maternity services for ethnic minority women
and ethnic minority women do not access or receive optimal care and that this can increase their risk of morbidity and death. Further research is needed to identify the barriers that prevent women from seeking care or maintaining contact with the maternity services. Reliable statistics are needed to understand the scale of the problem, as well as better monitoring and evaluation of the strategies implemented to address the health needs of women of ethnic minority groups. This should include assessment of the quality of care. There is no doubt that several groups have made substantial progress in ensuring that service delivery is effective, of a high standard and acceptable to women of ethnic minority background or immigrant status. It is important that such experiences and the lessons learned are more widely disseminated. Health Trusts in areas with significant populations from ethnic minority backgrounds should consider strategies to ensure improved communication with these women and their communities. Many of the interventions outlined above are incorporated in the UK Department of Health National Framework for Children, Young People and Maternity Services.22 Working in partnership and using a multidisciplinary approach is most likely to improve access to maternity services and, thus,
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obstetric outcome for ethnic minority women and their families. References 1 Department of Reproductive Health and Research, World Health Organization. Maternal Mortality Estimates 2005. Estimates Developed by WHO, UNICEF and UNFPA. Geneva: WHO; 2008 [http://www.who.int/reproductive-health/publications/maternal_ mortality_2005/index.html]. 2 Confidential Enquiry into Maternal and Child Health. Why Mothers Die 2000–2002. The Sixth Report of the Confidential Enquiries into Maternal Deaths in the United Kingdom. London: RCOG Press; 2004. 3 Lewis G, editor. Why Mothers Die. The Fifth Report of the Confidential Enquiries into Maternal Deaths in the United Kingdom, 1997–1999. London: RCOG Press; 2001. 4 Confidential Enquiry into Maternal and Child Health. Saving Mothers’ Lives. The Seventh Report of the Confidential Enquiries into Maternal Deaths in the United Kingdom. London: CEMACH; 2007. 5 The Office of National Statistics. Ethnicity and identity [www.statistics.gov.uk/focuson/ethnicity/]. 6 Versi E, Liu K, L, Chia P, Seddon G. Obstetric outcome of Bangladeshi women in east London. Br J Obstet Gynaecol 1995;102:630–7. 7 Ibison J M. Ethnicity and mode of delivery in ‘low-risk’ first-time mothers, East London, 1988–1997. Eur J Obstet Gynecol Reprod Biol 2005;118:199–205. doi:10.1016/j.ejogrb.2004.05.002 8 Parsons L, Day S. Improving obstetric outcomes in ethnic minorities: an evaluation of health advocacy in Hackney. J Public Health Med 1992;14:183–91. 9 Ibison JM, Swerdlow AJ, Head JA, Marmot, M. Maternal mortality in England and Wales 1970–1985: an analysis by country of birth. Br J Obstet Gynaecol 1996;103:973–80. 10 RCOG Clinical Effectiveness Support Unit. National Sentinel Caesarean Section Audit Report. London: RCOG Press; 2001. 11 Yoong W, Wagley A, Fong C, Chukwuma C, Nauta M. Obstetric performance of ethnic Kosovo Albanian asylum seekers in London: a case-control study. J Obstet Gynaecol 2004;24:510–2. doi:10.1080/01443610410001722527 12 Yoong W, Wagley A, Fong C, Chukwuma C, Nauta M. The obstetric performance of United Kingdom asylum seekers from Somalia: a case control study and literature review. Int J Fertil Womens Med 2005;50:4;175–9 13 Bulman KH, McCourt C. Somali refugee women’s experiences of maternity care in West London: a case study. Critical Public Health 2002;12:365–80. doi:10.1080/0958159021000029568 14 Rowe RE, Garcia J. Social class, ethnicity and attendance for antenatal care in the United Kingdom: a systematic review. J Public Health Med 2003;2:113–9. doi:10.1093/pubmed/fdg025 15 Petrou S, Kupek E, Vause S, Maresh M. Clinical, provider and sociodemographic determinants of the number of antenatal visits in England and Wales. J Social Science and Medicine 2001;52:1123–34. doi:10.1016/S0277-9536(00)00212-4 16 Woollett A, Dosanjh-Matwala N. Pregnancy and antenatal care: the attitudes and experiences of Asian women. Child Care Health Dev 1990;16:63–78. doi:10.1111/j.1365-2214.1990.tb00639.x 17 Kupkep E, Petrou S, Vause S, Maresh M. Clinical, provider and sociodemographic determinants of late initiation of antenatal visits in England and Wales. BJOG 2002:109:265–73.
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18 Firdous R, Bhophal RS. Reproductive health of Asian women. A comparative study with hospital and community perspectives. Public Health 1989;103:307–15. doi:10.1016/S0033-3506(89)80045-9 19 Sikorski, J, Clement S, Wilson J, Das S, Smeeton, N. A survey of health professionals’ views on possible changes in the provision and organisation of antenatal care. Midwifery 1995;11:61–8. doi:10.1016/0266-6138(95)90068-3 20 D’Souza L, Garcia J. Improving services for disadvantaged childbearing women. Child Care Health Dev 2004;30:599–611. doi:10.1111/j.1365-2214.2004.00471.x 21 Bowes AM, Domokos TM. Pakistani women and maternity care: raising muted voices. Sociol Health Illn 1996;18:45–65. doi:10.1111/14679566.ep10934412 22 Department of Health, Department for Education and Skills. National Service Framework for Children, Young People and Maternity Services: Maternity Services. London: The Stationery Office; 2004 [www.dh.gov.uk/ en/Publicationsandstatistics/Publications/PublicationsPolicyAndGuidance/ DH_4089101]. 23 Hayes L. Unequal access to midwifery care: a continuing problem? J Adv Nurs 1995;21:702–7. doi:10.1046/j.1365-2648.1995.21040702.x 24 McCourt C. Pearce A. Does continuity of career matter to women from minority ethnic groups? Midwifery 2000;16:145–54. doi:10.1054/midw.2000.0204 25 Ahmed S, Green J, Hewison J. What are Pakistani women’s experiences of antenatal carrier screening for beta-thalassaemia in the UK? Why it is difficult to answer this question? Public Health 2002;116:297–9. 26 Green JM, Renfrew MJ, Curtis AP. Continuity of carer: what matters to women? A review of the evidence. Midwifery 2000;16:186–96. doi:10.1054/midw.1999.0208 27 McLeish J. Mothers in Exile: Maternity Experiences of Asylum Seekers in England. London: Maternity Alliance; 2002 [www.icar.org.uk/?lid=4400b]. 28 Department of Health. Independent Inquiry into Inequalities in Health Report. London: The Stationery Office; 1998. 29 Daniel K. Travellers’ friend. Nursing Times 1995;95:32–3. 30 Pahl J, Vaile M. Health and health care among travellers. J Soc Policy 1988;17;195–214. 31 Parry G, Patrice Cleemput V, Peters J, Walters S,Thomas K and Cooper C Health status of Gypsies and Travellers in England J Epidemiol Community Health 2007;61;198–204 doi:10.1136/jech.2006.045997 32 Duff LA, Lamping DL, Ahmed LB. Evaluating satisfaction with maternity care in women from minority ethnic communities: development and validation of a Sylheti questionnaire. Int J Qual Health Care 2001;13:215–30. doi:10.1093/intqhc/13.3.215 33 Rocheron Y, Dickson R. The Asian Mother and Baby Campaign: a way forward in health promotion for Asian women? Health Education Journal 1990;49:128. doi:10.1177/001789699004900310 34 Mason E. The Asian Mother and Baby campaign (the Leicestershire experience). J R Soc Health 1990;110:1–4. doi:10.1177/146642409011000101 35 Warrier S. Consumer empowerment. A qualitative study of linkworker and advocacy services for non-English speaking users of maternity services. British Journal of Midwifery 1996;5:568–72. 36 MacCaffrey M, Jankowska A, Gordon H. Management of female genital mutilation; the Northwick Park Hospital experience. Br J Obstet Gynaecol 1995;102:787–90. 37 Anderson C, Rajyaguru R. The role of community pharmacists and medicines counter assistants in health promotion: reflections from a folic acid campaign. Int J Pharm Pract 2002;3:17–22.
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