Outcomes of pregestational compared to gestational diabetics amongst the ethnic
minority population in Birmingham, West Midlands.
Rinku Sengupta-Giridharan1, Pat Brydon2 and Fidelma Dunne 3.
1Specialist Registrar, Queens Hospital ,Burton Upon Trent, 2Research Midwife,
West Midlands Perinatal Institute, 3Consultant Diabetologist, Galway Hospital,
Northern Ireland.
Abstract:
Aims / Objectives: To compare the maternal and neonatal outcomes between gestational and
presentational diabetics in the ethnic minority population in Birmingham.
Background/Setting: University teaching hospital serving a multiethnic population of approximately
2.5 million. The diabetic clinic is run once a week with a dedicated Consultant obstetrician, a
Diabetologist, dietician, diabetic specialist nurse, midwives and ultrasonographers. Women with
gestational and pre gestational diabetes are seen in this clinic.
Materials and methods: The diabetic database between 1997 and 2003 identified 199/532 women
from the ethnic minority background. All data collected were prospective. Results were tabulated and
calculations performed on Microsoft Excel spreadsheet. P<.05 was taken as significant.
Results: 199(37.4%) women were of Indo-Asian origin, 33(6.2%) Afro-Caribbean and 30 Other (South
East Asian/ Middle-eastern, Chinese). 147(72%) of Indo -Asian women had gestational diabetes compared to 19 (58%)
Afro-Caribbean and 24 (83%) in the other group. On the other hand 52(26%) of Indo-Asian women had pre-gestational diabetes
compared to14 (42.4%) Afro-Caribbean women and 5(17%) in the other group.
The booking BMI was more or less the same in both the groups. However the time of antenatal
booking was significantly later in the gestational group than the pregestational group. (10 weeks vs. 14
weeks p<.01)Only 4 women in the pre gestational group attended the preconception counselling clinic.
The shoulder dystocia and LGA rates were higher in the gestational group even though the CS rates
were higher in the Type 2 diabetics. The NICU admissions (<32 weeks) were higher in the pre
gestational group .However 33-37 week NICU admission rates were higher in the gestational group.
Summary / Conclusions: Our study outlines the higher maternal adverse outcomes in the gestational
diabetic group contrary to other studies. However the perinatal mortality and the congenital
malformation rate are still higher in the pregestational group. This further stresses the need for strict
glycaemic control and an insight and awareness of the disease process and its adverse outcomes in
these groups of people. Black and ethnic minority populations suffer from inequalities of health and
discrimination; culture blaming and communication barriers may be contributory factors. We may need
to overcome these to improve the birth outcome figures in these groups of people.
Keywords: Diabetes, Outcome, Pregnancy, gestational.Pregestational.
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Introduction: Diabetes during pregnancy is associated with an increased risk of
adverse pregnancy outcomes in both the mother and the infant. This may be further
influenced by racial and cultural differences. Special attention is needed to overcome
language and sociocultural barriers in these groups of pregnant for effective health
care.
The prevalence of diabetes amongst women of childbearing age is increasing in the
United Kingdom. Immigration by populations with high or increasing diabetes
prevalence is also on the rise
The effects of acculturation on diabetes risk and the increasing prevalence of obesity
and delayed child bearing amongst women suggest the need for a systematic
surveillance of the prevalence and effect of diabetes during pregnancy amongst both
immigrant and non immigrant women particularly in ethnic and racial minority
groups.
Metabolic susceptibility to diabetes may exist before and become more marked after
migration which is possibly associated with physical inactivity, obesity, smoking,
psychosocial stress and dietary changes. (Maternal nativity and diabetes during
pregnancy)
Before the collection of data on ethnicity of births in Birmingham ceased in the mid
80’ it was noted that 1 in 3 births in the city was to a mother from a minority ethnic
group. Expert opinion suggests that this proportion is now nearer 1 in 2.3
Maternal ethnicity is a known risk factor for development of both gestational and
Type II diabetes. Recent evidence suggests that Type 2 diabetes is associated with
fetal death and birth defects to the same extent as Type 1 diabetes.4Women with Type
2 diabetes have a less satisfactory pregnancy outcome compared with the general
population. Infants have a two-fold greater risk of stillbirth, a 2.5-fold greater risk of a
perinatal mortality, a 3.5-fold greater risk of death within the first month and a sixfold greater risk of death up to 1 year compared with regional/national figures. They
have an 11 times greater risk of a congenital malformation. We need to develop better
educational and screening strategies if we are to improve.2
Type 2 diabetes is almost twice as likely as those with type 1 to have miscarriages and
congenital malformations. In addition their babies are more likely to be large for
gestational age and to be born before 37 weeks gestation. Unfortunately type 2
diabetes has long been, misguidedly, regarded by some as less severe than type 1 and
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this is clearly not the case. Indeed part of the reason for the adverse pregnancy
outcome in this group is the poor attendance for pre pregnancy care, later booking for
antenatal care and poor glycaemic control at booking.5
Gestational diabetes and impaired glucose tolerance (IGT) in pregnancy affects
between 3 and 6% of all pregnancies and both have been associated with pregnancy
complications. A lack of conclusive evidence has led clinicians to equate the risk of
adverse perinatal outcome with pre-existing diabetes.7
Previous studies by ray et al have shown that pregestational diabetes was at an
increased risk of operative delivery, shoulder dystocia, cephalo pelvic disproportion,
and gestational hypertension or preeclampsia. The offspring were also at an increased
risk of NICU admission, LGA birth weight and preterm labour. However they did not
control for maternal ethnicity in their study.
The recent antenatal care guidelines (NICE/RCOG 2003) have recommended ‘the
evidence does not support routine screening for gestational diabetes mellitus and
therefore should not be offered.’(Grade b)However they have not taken ethnicity into
account.
The purpose of our study was to see whether race and ethnicity made a difference in
the outcomes in pregestational diabetes compared to gestational diabetes.
Methods: The study was performed in a university teaching hospital with a large fetal
medicine unit serving a multi ethnic population of approximately 2.5 million. Women
with pre gestational diabetes are encouraged to register early for antenatal care and
are assigned a single obstetrician with an interest in diabetes in pregnancy. For
women who develop impaired glucose tolerance or gestational diabetes in the index
pregnancy their obstetric care is transferred to the designated obstetrician. Diabetes
care is provided by the Department of Diabetes Care, Division of Medical Sciences
University Hospital Birmingham.
Information about 262 women from the ethnic minority background delivered
between 1997 and 2003 was ascertained from a regional computerized
database.37.4% of all women who attended the diabetic clinic during the said period
were from an ethnic minority background.
All information on the index pregnancy is recorded on a computerized database and
clinical records were reviewed for a 6-year period. This study details the information
on all ethnic minority women registered on this database during this period and
compares fetal (miscarriage, i.e. fetal loss before <24 weeks gestation; stillbirth, i.e.
fetal loss >24 weeks gestation; neonatal deaths during the first 28 days of life;
perinatal mortality, i.e. stillbirths and neonatal deaths; congenital malformations;
10/02/05 Diabetes in pregnancy outcomes.
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infant size at delivery) and maternal (mode of delivery, i.e. caesarean section vs.
vaginal deliveries; time of delivery, i.e. preterm <37 weeks vs. term deliveries)
outcomes in the two groups.
Gestational diabetes mellitus (GDM) and impaired glucose tolerance (IGT) were
diagnosed using a 75 g oral glucose tolerance test and WHO values of >7.8 mmol/l
fasting and >11.1 mmol/l at 2 h for GDM, and 5.6–7.8 mmol/l fasting with a 2 h value
of 7.8–11.1 for IGT. Type 1 and type 2 diabetes were defined on the basis of history
of disease onset and treatment.
Fishers exact test and Mann Whitney test were used where appropriate, with p<0.05
taken as significant.
Results: 199(76%) women were of Indo-Asian origin, 33(12.5%) Afro-Caribbean 30
(11.4%) belonged to the other group (South East Asian/Middle-eastern, Chinese)
amongst the 262/532(49.2%) women identified on the database during that period
from an ethnic minority background. 188(71.7%) of them were gestational diabetics
(IGT/GDM) and 74(55.6%) of these pregestational. (IDDM/NIDDM/MODY.)
Only 4 /74(5.4%) patients in the pregestational group attended the pre conception
counselling clinic. No attendance was recorded in the gestational group on the
database.
Ethnic
minority
population
7.6
Stillbirth
rate/1000
NND/1000 22.9
PMR/1000 26.7
CAR/1000 76.3
All
Hospital
Regional
diabetics population (National)
at BWH
11
9.0
5.5 (5.0)
North
East
Region
19
North
West
Region
25
23
34
97
29
48
83
11
36
94
12
21
5.4(6.8)
9.9(8.3)
9.5
Table 1: CAR = Congenital anomaly Rate, NND = Neonatal Death, PMR =
Perinatal Mortality Rate BWH Birmingham women’s hospital. (Data reproduced with
permission from Mr. J.Gardosi. Director, West Midlands Perinatal Institute.)
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Table 2: Age, body mass index (BMI), duration of diabetes mellitus (DM), first
attendance at antenatal clinic (ANC) and parity in ethnic minority women with
diabetes in pregnancy
Pregestational
Gestational
(IDDM/NIDDM.MODY) (IGT/GDM)
P
BMI
(kg/m2)
29.6+/-6.37
P=0.9
ANC
(weeks)
10.7+/-5.3
14.2+/- 4.4
parity
3.8 +/- 2.4
3.6+/-2.4
29.8+/-6.17
VALUES
P=<.0001
P=0.35
Values are means±SD. IGT, impaired glucose tolerance; GDM, gestational diabetes
mellitus.
Table 3: Gestational size at delivery in the ethnic minority population.
Pregestational. n=64
Gestational n=186
Total n=250*
values
AGA
69 %(44)
60% (112)
62.4%(156)
P =.2
LGA
13%(8)
23%(43)
20.4%(51)
P<=.07
SGA
19 % (12)
17.2%(43)
P=.7
16.6% (31)
AGA, appropriate for gestational age, i.e. between 10–90th centile; LGA, large for
gestational age, i.e. >90th centile; SGA, small for gestational age, i.e. <10th centile.
*12 patients no information reguarding gestational size could be obtained from the
database.
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Table 4: Mode of delivery—vaginal including vaginal breech delivery and
instrumental delivery rates (V) and caesarean section (CS) in ethnic minority
population women with diabetes mellitus whose pregnancy continued beyond 24
weeks
Type of diabetes
Vaginal delivery
Caesarean section
Total
136 (53)% (n=256)
120 (47)%
(n=256)
Type 1
Type 2
9 (56.2)% (n=16)
23 (44.2)% (n=52)
GDM/IGT
104 (55.3)%
(n=188)
7 (43.7)% (n=16)
29 (55.7)%
(n=52)
84 (44.6)%
(n=188)
Other abbreviations as Table 1.
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Table 5: Characteristics of singleton women with gestational and pregestational
diabetes mellitus, as well as gestational age and neonatal birth weight at delivery
Characteristic
Gestational
diabetes mellitus
(n=188)
Pre gestational
diabetes mellitus
(n=74)
Statistical
comparison
between groups
No. (%)
primigravidae
No. (%) prior
Caesarean section*
No. (%) previous
stillbirth or
neonatal death
Mean BMI (kg/m2)
(SD, 95%CI) prepregnancy
Mean (SD, 95%CI)
gestational age at
current delivery
(weeks)
Mean (SD, 95%CI)
neonatal birth
weight at current
delivery (g)
Congenital
Anomalies
Miscarriage < 24
weeks
Stillbirths/ENND/
LNND/PNND
33 (17.5)
14 (19)
p=0.8
25 (13.2)
11 (14.8)
p=0.8
13 (6.9)
6 (8.1)
p=0.7
29.8 (6.1, 28.8–
30.8)
29.7 (6.4, 28.1–
31.3)
p<0.001
37.6 (2.7, 37.2–
38.0)
33.2 (10.6, 30.7–
35.6)
3.264 (.7215,
3.160–3.369)
2.976 (.8476,
2.766-3.186)
22(11.7%)
13(17.5%)
P=.2
3(1.5%)
10(13.5%)
P<.0002
3(1.5%)
5(6.7%)
P<.04
**BMI data were unavailable for 36 (19%) women with gestational DM and 11
(15%) with pregestational DM. BMI, body mass index; NA, not applicable.
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Table 6: Rates and odds ratios (OR) for neonatal outcomes among women with
pregestational and gestational diabetes mellitus.
Maternal
characteristics
NICU
admission
LGA
Preterm birth
20-32 weeks
Preterm birth
33-37 weeks
Rate
(%)
OR*
Rate
(95%CI) (%)
OR*
Rate
(95%CI) (%)
OR*
Rate
(95%CI (%)
13
1.0677
(0.4835
to
2.3579)
0.4751
(0.2102
to
1.0738)
0.7102 23.4
(
0.2259
to
2.2325)
OR*
(95%CI
Diabetes
mellitus type
Gestational
Pregestational
14
23
13
2.6
5.4
1.3(.642.7)
18.9
Discussion:
Previous studies7 have shown that women with pregestational diabetes mellitus were
at an increased risk of operative delivery and shoulder dystocia and caesarean section
compared to gestational diabetics. The offspring in these women were at a significant
increased risk for NICU (neonatal intensive care unit) admission, LGA (large for
gestational age) birth weight and preterm delivery. 1
We wanted to see whether the same differences were maintained in the ethnic
minority group.
There were several limitations in our study. Firstly the absence of a control group
without diabetes mellitus from the ethnic minority population itself. Other studies 4
have established this point but have not considered nondiabetic ethnic minority
controls.
We also did not account for the different sub groups of the ethnic minority population.
It is well known that the incidence of GDM/Type 2 diabetes is more common
amongst the Indo Asian population than in other ethnic minority populations.
However the Indo Asian population did count for almost 76% of our study population.
Neither the clinicians nor the patients were blinded in the study as to the type of
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patient and the outcome measure and the treatment received. Furthermore maternal co
morbidity was not accounted for either.1
The interesting finding in our study is the shoulder dystocia rate, the instrumental
delivery rate and the incidence of large for date babies are actually higher in the
gestational subgroup compared to the pregestational subgroup. However the
miscarriage rate, the congenital anomaly rate and the stillbirth is still significantly
higher in the pre gestational group as proven in earlier studies.1
The very poor attendance in the pre pregnancy counselling clinics (4/74 in the
pregestational vs. 0/188 in the gestational) needs to be addressed as well. The need for
special pre pregnancy counselling clinics has been questioned because they tend not
to attract those with poor control who at most risk and many pregnancies are
unplanned. Therefore the role of the GP, diabetologist, and the diabetic nurse
specialist are crucial. Many women may not be aware that they have type 2 diabetes
clearly making preconceptual care impossible.2
Thus compared to non diabetic general hospital deliveries(table 1 )the perinatal
mortality and the congenital malformation rate is still almost five times higher in the
diabetic ethnic minority population(pregestational > gestational).This defeats the goal
of the St Vincent’s declaration that states that the outcome of diabetic pregnancy
should approximate that of non diabetic pregnancy.
In non diabetic populations perinatal and neonatal mortality rates are greater In
women from ethnic minority backgrounds ,It has been argued that Black and ethnic
minority populations suffer inequalities in health and authors highlight discrimination
communication barriers and culture blaming as contributory factors to adverse birth
outcome.3 There are suggestions in the midwifery literature that there is unequal
access to midwifery care among the ethnic minority groups and the the care available
may be inadequate ,inaccessible and inappropriate.3
Our results indicate the pregnancy outcomes are poorer in the gestational (maternal)
and the pregestational(fetal) groups from the ethnic minority population. These may
be partly overcome by education, communication and better delivery of services. This
shows only a trend.
Future better designed trials are needed to compare outcomes in diabetic with
nondiabetic ethnic minority populations after proper calculation of sample size to
reduce sampling errors.
References:
10/02/05 Diabetes in pregnancy outcomes.
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M.J. Vermeulen3, J.L. Shapiro4 and A.B. Kenshole1 Q J Med 2001; 94: 347-356
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