title: Ethnic variations in severe maternal morbidity in the UK- a case control study.
abstract: BACKGROUND
  Previous studies showed a higher risk of maternal morbidity amongst black and other minority ethnic (BME) groups, but were unable to investigate whether this excess risk was concentrated within specific BME groups in the UK. Our aim was to analyse the specific risks and to investigate reasons for any disparity.
  
  
  METHODS
  Unmatched case-control analysis using data from the United Kingdom Obstetric Surveillance System (UKOSS), February 2005-January 2013. Cases were 1,753 women who experienced severe morbidity during the peripartum period. Controls were 3,310 women who delivered immediately before the cases in the same hospital. Multivariable logistic regression modelling was used to adjust for known confounders and to understand their effects.
  
  
  RESULTS
  Compared with white European women, the odds of severe maternal morbidity were 83% higher among black African women (adjusted odds ratio (aOR) = 1.83; 95% Confidence Interval (CI) = 1.39-2.40), 80% higher among black Caribbean (aOR = 1.80; 95% CI = 1.14-2.82), 74% higher in Bangladeshi (aOR = 1.74; 95% CI = 1.05-2.88), 56% higher in other non-whites (non-Asian) (aOR = 1.56; 95% CI = 1.05-2.33) and 43% higher among Pakistani women (aOR = 1.43; 95% CI = 1.07-1.92). There was no evidence of substantial confounding. Anaemia in current pregnancy, previous pregnancy problems, inadequate utilisation of antenatal care, pre-existing medical conditions, parity>3, and being younger and older were independent risk factors but, the odds of severe maternal morbidity did not differ by socioeconomic status, between smokers and non-smokers or by BMI.
  
  
  CONCLUSIONS
  This national study demonstrates an increased risk of severe maternal morbidity among women of ethnic minority backgrounds which could not be explained by known risk factors for severe maternal morbidity.
authors.affiliation: National Perinatal Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom.
authors.forename: Manisha
authors.initials: M
authors.lastname: Nair
authors.affiliation: National Perinatal Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom.
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Kurinczuk
authors.affiliation: National Perinatal Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom.
authors.forename: Marian
authors.initials: M
authors.lastname: Knight
mesh_terms: D000328:Adult; D000367:Age Factors; D000740:Anemia / Q000208:ethnology* / Q000401:mortality*; D044383:Black People; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000208:ethnology* / Q000401:mortality*; D012307:Risk Factors; D012959:Socioeconomic Factors; D006113:United Kingdom / Q000453:epidemiology / Q000208:ethnology
references.citation: Obstet Gynecol. 2010 May;115(5):989-997
references.pmid: 20410773
references.citation: Obstet Gynecol. 2010 May;115(5):910-917
references.pmid: 20410762
references.citation: BJOG. 2008 Sep;115(10):1265-72
references.pmid: 18715412
references.citation: BJOG. 2008 Mar;115(4):453-61
references.pmid: 18201281
references.citation: BJOG. 2008 Jun;115(7):842-50
references.pmid: 18485162
references.citation: Health Stat Q. 2008 Autumn;(39):22-31, 34-55
references.pmid: 18810886
references.citation: PLoS One. 2011;6(12):e29077
references.pmid: 22216171
references.citation: PLoS Med. 2012;9(3):e1001184
references.pmid: 22427745
references.citation: BMJ Open. 2013 Jun 20;3(6):
references.pmid: 23794588
references.citation: Stud Fam Plann. 1998 Dec;29(4):341-59
references.pmid: 9919629
references.citation: Acta Obstet Gynecol Scand. 2012 Jul;91(7):824-9
references.pmid: 22404729
references.citation: PLoS One. 2013 Jul 02;8(7):e67175
references.pmid: 23843991
references.citation: BJOG. 2007 Nov;114(11):1380-7
references.pmid: 17877772
references.citation: Lancet. 2006 Sep 30;368(9542):1189-200
references.pmid: 17011946
references.citation: Ann Epidemiol. 2011 Feb;21(2):73-7
references.pmid: 21184949
references.citation: Reprod Health Matters. 2011 May;19(37):144-53
references.pmid: 21555095
references.citation: Am J Obstet Gynecol. 2005 Feb;192(2):592-7
references.pmid: 15696008
references.citation: Obstet Gynecol. 2012 Aug;120(2 Pt 1):318-24
references.pmid: 22825091
references.citation: Eur J Public Health. 2011 Apr;21(2):229-34
references.pmid: 20522516
references.citation: Am J Obstet Gynecol. 1998 Feb;178(2):346-54
references.pmid: 9500498
references.citation: Anesthesiology. 2011 Nov;115(5):963-72
references.pmid: 21934482
references.citation: PLoS One. 2012;7(12):e52893
references.pmid: 23300807
references.citation: Am J Obstet Gynecol. 1992 May;166(5):1339-44
references.pmid: 1595788
references.citation: BMJ. 2009 Mar 03;338:b542
references.pmid: 19261591
references.citation: BJOG. 2005 Mar;112(3):263-5
references.pmid: 15713136
references.citation: Am J Public Health. 2003 Apr;93(4):631-4
references.pmid: 12660209
references.citation: BJOG. 2012 Mar;119(4):474-83
references.pmid: 22251396
references.citation: BMJ. 2001 May 5;322(7294):1089-93; discussion 1093-4
references.pmid: 11337436
references.citation: Afr J Reprod Health. 1997 Mar;1(1):14-24
references.pmid: 10214399
references.citation: BMC Pregnancy Childbirth. 2013 May 03;13:103
references.pmid: 23642084
references.citation: BJOG. 2007 Sep;114(9):1072-8
references.pmid: 17617191
references.citation: Int J Epidemiol. 1999 Oct;28(5):964-74
references.pmid: 10597998
references.citation: J Perinatol. 2007 Oct;27(10):597-601
references.pmid: 17703181
references.citation: J Epidemiol Community Health. 1998 May;52(5):293-7
references.pmid: 9764279
references.citation: Bull World Health Organ. 2010 Feb;88(2):113-9
references.pmid: 20428368
references.citation: Public Health. 2008 Dec;122(12):1363-72
references.pmid: 18639909
references.citation: Popul Dev Rev. 2010;36(3):441-86
references.pmid: 20882702
references.citation: Obstet Gynecol. 1997 Aug;90(2):225-9
references.pmid: 9241298
references.citation: BJOG. 2011 Mar;118 Suppl 1:1-203
references.pmid: 21356004
references.citation: Gut. 2008 Jul;57(7):951-6
references.pmid: 18332072