This document discusses influences of ethnicity on obstetric outcomes in London hospitals. It finds that different ethnic groups have varying gestational length distributions, rates of prematurity, and fetal lung maturation. For example, Black Africans have earlier lung maturation compared to White Europeans. The document also finds ethnic differences in rates of cesarean delivery, meconium staining, and neonatal respiratory issues that vary by gestational age. Overall, the findings suggest ethnic-specific genetic and physiological differences that influence pregnancy and neonatal outcomes.

1. New approaches to
Maternal Mortality in Africa
What are the influences of maternal ethnic
background on obstetric outcomes in
London Hospitals today?
2nd July 2012
P J Steer
Emeritus Professor of Obstetrics
Academic Department of Obstetrics and Gynaecology
Chelsea and Westminster Hospital
1
© Imperial College London

2. What is ‘Ethnicity’?
• ‘Ethnicity’ relates to factors such as
culture, ancestry, language and beliefs
• Different from ‘Race’, which refers to:
• Physical characteristics associated with
distinct populations identified by
heritable phenotype or geographic
ancestry

3. Race/ethnicity mismatch
hypothesis
• Nutrition and environment (‘ethnicity’)
have a major influence on racial
evolution
• Changes in ethnicity can disadvantage
some racial groups
• E.g. Latino immigrants into the USA
develop very high rates of obesity*
*
Williams JE et al, Ethn Dis 2011;21:467-72

4. NorthWest Thames Obstetric
Database 1988-2000
• 17 maternity units
• On-line validation of data entry
• 501,823 births
• Perinatal deaths crosschecked with the
Office of National Statistics

5. White European 362,630
Black African 17,095
Black Caribbean 14,557
South Asian 66,409

6. 14
12
10
Perinatal 8
mortality 6
4
2
0
White Black Black South
European African Caribbean Asian

7. Ethnicity?

8. Black Caribbean
Black African
South Asian
White European
Affluent Poor

11. White European
Black Caribbean
Black African
South Asian

12. Some genetic conditions vary
substantially between races
• Sickle disease West Africans
• β thalassaemia Eastern Mediterraneans
• Cystic fibrosis Anglo-Saxons
• Haemochromatosis Celts

13. Have the various races evolved
other important genetic
differences in relation to
childbirth?

14. Gestational length distribution is different
44
42
40
38
Gestation (weeks)
36
34
32
30
28
26
24
0
20
10
40
30
Patel RR, Steer PJ, Doyle P, Little M, Elliott P. 2004 Int J Epidemiol;33:107-113
Frequency (%)

15. Gestational length distribution is different
40
Whites
30
Frequency (%)
20
10
0
24 26 28 30 32 34 36 38 40 42 44
Gestation (weeks)
Patel RR, Steer PJ, Doyle P, Little M, Elliott P. 2004 Int J Epidemiol;33:107-113

16. Gestational length distribution is different
40
Whites
30
Frequency (%)
South Asians &
20 Blacks
10
0
24 26 28 30 32 34 36 38 40 42 44
Gestation (weeks)
Patel RR, Steer PJ, Doyle P, Little M, Elliott P. 2004 Int J Epidemiol;33:107-113

17. Earlier maturation of the lungs
in fetuses of black African origin
• Farrell PM,.Wood RE. Epidemiology of hyaline membrane disease in the United States:
analysis of national mortality statistics. Ped 1976;58:167-76.
• Buehler JW, Strauss LT, Hogue CJ, Smith JC. Birth weight-specific causes of infant mortality,
United States, 1980. Public Health Reports 1987;102:162-71.
• Coulter JB. The incidence of the respiratory distress syndrome:
with particular reference to developing countries.
Tropical & Geographical Medicine 1980;32:277-85.
• Richardson DK,.Torday JS. Racial differences in predictive value of the
lecithin/sphingomyelin ratio. Am J Obstet Gynecol 1994;170:1273-8.
• Robillard PY, Hulsey TC, Alexander GR, Sergent MP, de Caunes F, Papiernik E.
Hyaline membrane disease in black newborns: does fetal lung maturation occur earlier?
Europ J Obstet Gynecol Reprod Biol 1994;55:157-61.
• Berman S, Richardson DK, Cohen AP, Pursley DM, Lieberman E.
Relationship of race and severity of neonatal illness. Am J Obstet Gynecol 2001;184:668-72.

18. Proportion of babies transferred to Special Care +/- SE 1.2
1.0
0.8
0.6
0.4
Black African
White European
0.2
0.0
24 26 28 30 32 34 36 38 40 42 44
Weeks gestation at birth
P. Steer. Prematurity or immaturity?
BJOG. 2006;113 Suppl 3:136-138

19. Proportion with meconium stained amniotic fluid +/- SE
0.5
0.4
Black African
White European
0.3
0.2
0.1
0.0
26 28 30 32 34 36 38 40 42 44
Weeks gestation at birth
P. Steer. Prematurity or immaturity?
BJOG. 2006;113 Suppl 3:136-138

20. Imelda Balchin,
JC Whittaker
RF Lamont,
PJ Steer,
Obstet Gynecol 2011;
117:828–835

21. I Balchin, J. C. Whittaker, R. R. Patel, R. F. Lamont, and P. J. Steer.
Racial variation in the association between gestational age and perinatal mortality:
prospective study. BMJ, 2007.

22. Gestation specific transient tachypnoea of the
newborn/respiratory distress syndrome in infants who
had planned Cesarean delivery
White European
Timing of planned Cesarean
South Asian Delivery by Racial Group
Imelda Balchin, JC Whittaker,
RF Lamont, PJ Steer
Obstet Gynecol 2008;
White European 111:659–66
Black

23. Page 29
Research is needed into racial
differences in the UK to identify the
possible differences in the
distribution of perinatal risk specific to
gestational weeks and possible
benefits of intervention before 41
weeks.

24. Africans have a narrower pelvis
• Narrower pelvis aids
stability when running
• Lumbar lordosis/ high
assimilation improves
backward thrust
• Heavier bones mean
fewer stress fractures
• (less need for HRT)

25. Obstructed labor injury complex: obstetric fistula
formation and the muti-faceted morbidity of
maternal birth trauma in the developing world
Arrowsmith, S., Hamlin, E.C., Wall, LL. 1996
Obstetrical and Gynecological Survey 51: 568 - 574
New cases of obstetric fistula up to 500,000 per year
worldwide

26. More than 2 million African women suffer
from untreated obstetric fistula (vesicovaginal or rectovaginal),
a condition that is a consequence of
untreated obstructed labor
There is a backlog
of almost
1,000,000
untreated cases in
Northern Nigeria
alone
F. Donnay and L. Weil.
Obstetric fistula:
the international response.
Lancet 363 (9402):71-72, 2004.

27. VESICO-VAGINAL FISTULA REPAIR
In Kano, Northern Nigeria
Dr Kees Waaldijk. In 1995 he performed 1,184 VVF repairs as part of the
National Task Force of Nigeria. From ORGYN 1 1997 (Organon International)

28. WOMEN WAITING FOR
V V F REPAIR

29. Addis Ababa
Fistula Hospital

30. Caesarean section rates
in London, 1998
(81,019 births, 67,110 with ethnicity data)
30
25
20
Elective %
15
Emergency %
10
5
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32. White European
Black African
Black Caribbean
South Asian
Balchin I, Steer PJ Early Hum Development (2007) 83, 749-754

33. White European
Black African
South Asian
Black Caribbean

34. An important influence on
birthweight is gestational
diabetes

35. Study numbers
Racial group Non-GDM GDM
White European 130,325 876
Black African 4,840 87
Black Caribbean 4,648 50
South Asian 19,685 401

44. Z
score
BMI

45. Z
score
BMI

46. Z
score
BMI

47. Z
score
BMI

48. White Europeans Blacks South Asians
Birthweight Z score is higher in GDM only if
the mother’s BMI is increased

49. The diabetic pregnancy and offspring BMI in childhood:
a systematic review and meta-analysis
• Maternal diabetes is associated with
increased offspring BMI z score
• This is no longer apparent after adjustment
for maternal pre-pregnancy BMI
Philipps LH, Santhakumaran S, Gale C, Prior E, Logan KM, Hyde MJ, Modi N.
Diabetologia. 2011 Aug;54(8):1957-66. Epub 2011 May 31.

50. Conclusions
• Both racial origin and ethnicity affect
obstetric performance
• This has important implications for:
• Monitoring fetal growth
• Timing of delivery
• Intrapartum care

51. Intrauterine Factors, adiposity and hyperinsulinaemia
Prentice, A. BMJ 2003;327:880-1

52. Persistence of lower birthweight in second generation
South Asian babies born in the United Kingdom
Margetts BM, et al, J Epidemiol Community Health 2002;56:684-687

53. Birthweight centile charts for South Asian Infants
born in the UK
Seaton SE et al, Neonatology 2011;100:398-403

54. Genetic influence
(ONS data 1975-2000)
Georgina Ronalds Dave Leon
N = 4149 136 190 121307

55. Consensus statement for diagnosis of obesity,
abdominal obesity and the metabolic syndrome for
Asian Indians
Asian Indians exhibit unique features of obesity;
•excess body fat,
•abdominal adiposity,
•increased subcutaneous and intra-abdominal fat,
•deposition of fat in ectopic sites (liver, muscle, etc.).
Obesity is a major driver for the widely prevalent
metabolic syndrome and type 2 diabetes mellitus (T2DM)
in Asian Indians in India and those residing in other countries.
Based on percentage body fat and morbidity data,
limits of normal BMI are narrower and lower in Asian Indians
than in white Caucasians.
Misra A, et al. J Assoc Physicians India. 2009 Feb;57:163-70

56. Obesity-related non-communicable diseases:
South Asians vs White Caucasians
• South Asians are at higher risk than White Caucasians for the
development of obesity and obesity-related non-communicable
diseases
• Determinants include:
– high body fat, high truncal, subcutaneous and intra-abdominal fat, and low
muscle mass
– hyperinsulinemia, hyperglycemia, dyslipidemia, hyperleptinemia, low levels
of adiponectin and high levels of C-reactive protein, procoagulant state and
endothelial dysfunction
• Lower cut-offs for obesity and abdominal obesity have been
advocated for Asian Indians
– BMI; overweight >23 to 24.9 kg m(-2)
– obesity ≥ 25 kg m(-2);
– WC; men ≥ 90 cm and women ≥ 80 cm, respectively
Misra A, Khurana L. Int J Obes (Lond). 2011 Feb;35(2):167-87. Epub 2010 Jul 20.

57. The thin-fat phenotype and global
metabolic disease risk
• The thin-fat phenotype occurs when fat is added to
an already thin frame
• The thin-fat phenotype may be programmed during
fetal growth
• the weight of evidence appears to link the thin-fat
phenotype to an environmental and lifestyle
phenomenon occurring in previously thin people
• This is particularly relevant in India, given the pace of
transition over the last two decades
Kurpad AV, Varadharajan KS, Aeberli I.
Curr Opin Clin Nutr Metab Care. 2011 Nov;14(6):542-7.

58. The influence of maternal body mass
index on infant adiposity and hepatic lipid
content
• Infant abdominal AT and liver lipid increase with
increasing maternal BMI across the normal range.
• These effects may be the initiating determinants of a
life-long trajectory leading to adverse metabolic
health
Modi N et al, Pediatr Res. 2011 Sep;70(3):287-91.

59. Whole body magnetic resonance imaging of
healthy newborn infants demonstrates
increased central adiposity in Asian Indians
• Abdominal adiposity and metabolic ill health in Asian Indians are
a growing public health concern
• Although smaller in weight, head circumference, and length,
the Asian Indian neonates had significantly greater absolute
adiposity in all three abdominal compartments in comparison to
the white European babies despite similar whole body adipose
tissue content
• Preventive measures must involve maternal health, intrauterine
life, and infancy
Modi N, Thomas EL, Uthaya SN, Umranikar S, Bell JD, Yajnik C
Pediatr Res. 2009 May;65(5):584-7.

60. CONCLUSIONS
• Maternal age and BMI are important risk factors for
GDM
• Maternal age is more important in Black Africans and
South Asians than in White Europeans
• BMI is particularly important in South Asians,
especially in relation to birthweight
• Strategies to reduce the incidence of GDM and type
2 diabetes will need to target preconception
counselling, maternity care, and infant feeding