Gestational diabetes mellitus (GDM) is a type of diabetes that is first recognized during pregnancy. An oral glucose tolerance test is used to diagnose GDM, with abnormal fasting or post-meal blood glucose levels indicating GDM. Women with GDM are at higher risk of complications during pregnancy like preeclampsia and delivering a large baby, so treatment focuses on maintaining normal blood glucose levels through diet, exercise, and possibly insulin or metformin. After delivery, women with GDM have an increased long-term risk of type 2 diabetes and should undergo screening.

1. GESTATIONAL DIABETES
MELLITUS(GDM)
Dr Najia Bhatti
(FCPS, Obs/Gyn unit II, SZWH,larkana )

2. DEFINITION OF GDM
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 The definition of Gestational diabetes from
National Data Group (1985) is : “Carbohydrate
intolerance of variable severity with onset or
first recognition during the presence of
pregnancy”
 It also includes women with pre-existing but
previously unrecognized diabetes.
 GDM: impaired carbohydrate tolerance
resulting in hyperglycemia which is identified
first time during pregnancy.

3. OGTT
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 The oral glucose tolerance test (OGTT)
measures the body's ability to use a type of
sugar, called glucose, that is the body's main
source of energy. An OGTT can be used to
diagnose prediabetes and diabetes
 Over night fast for 8 hours is required for it
then 75mg of glucose is taken orally after
taking a fasting glucose and two readings at
one hour and two hours after ingestion are
taken.
 Values are then interpearted according to
criteria.

4. Normal Blood Glucose Levels
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 For the majority of healthy individuals, normal
blood sugar levels are Between 4.0 to 6.0
mmol/L (72 to 108 mg/dL) when fasting. Up to
7.8 mmol/L (140 mg/dL) 2 hours after eating.
 Impaired glucose tolerance (IGT):
FBS<7.0mmol/l 2hours > 7 .8 mmol/l but
<11mmol/l.
 Diabetes in non pregnant: RBS >11mmol/l,
FBS >7.0 mmol/l, or 2 hour glucose
>11mmol/l on 75mg OGTT.

5. Incidence of GDM
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 Using definition of IGT in non pregnant woman
the incidence is about 3%-6%.
 Using the new diagnostic criteria by the
International Association of the diabetes and
pregnancy study group (IADPSG), the
frequency of GDM was 18% but varied from
9% to 26% in different countres.
 High risk in south asian women
(india,pakistan,and bangladesh) who have a
relative risk 7.6 to 11 fold.

6. Risk factors for screening GDM
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 First degree relatives with diabetes :
Type I: 15% Type II : 6.7%
 Previous baby 4.5 kg or more : 12.2%
 Glycosuria : 50% Be aware that glycosuria of
2+ or above on 1 occasion or of 1+ or above
on 2 or more occasions detected by reagent
strip testing during routine antenatal care may
indicate undiagnosed gestational diabetes. If
this is observed, consider further testing to
exclude gestational diabetes.

7. Risk factors for screening GDM
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 Current suspected macrosomia and
polyhydroamnios (both 40%)
 Previous Gestational Diabetes: recurrence
rate 30% to 84%
 Body mass index >30 kg/m2
 Ethinic origin: south asia (pak, bangladesh,
india) black caibbean, middle eastern ( saudi
arabia, UAE, jorden, oman, syria, qater,
kuwait, egypt.)

8. IMPORTANCE OF GDM
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 Increased risk of developing DM type II in 10-15
years.
 Undiagnosed DM type I, so increased risk of
ketoacidosis.
 Higher incidence of Macrosomia and adverse
pregnancy outcomes.
 Increased risk of Pre-eclampsia,
polyhydroamnios, IUD, still births,operative
delivery.
 Increased risk of preterm, macrosomia, late still
birth, hypoglycemia, ARDS, polycythemia,
juandice and neonatal mortality.

9. Screening And Diagnosis
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 NICE advocate screening only women with
risk factors with an OGTT at 24-28 weeks
gestation.
 Women with previous GDM should be offered
self monitoring of blood glucose or be
screened with an OGTT at 16-18 weeks and
again at 28 weeks if this is negative.
 NICE does not recommend screening with
random blood glucose, fasting blood glucose,
urinalysis or glucose challenge test.
 HbAIc should not be used as screening

10. NICE criteria for GDM
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According to NICE diabetes in pregnancy 2015 a
diagnosis of GDM is made if the:
Fasting plasma glucose is 5.6 mmol/liter or more
(100 mg/dl)
Or the two hour level is 7.8mmol/liter or more
(140mg/dl)s

11. HAPO study/IADPSG
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 The Hyperglycemia and Adverse Pregnancy Outcome
(HAPO) study was performed in response to the need for
internationally agreed upon diagnostic criteria for gestational
diabetes, based upon their predictive value for adverse
pregnancy outcome. Increases in each of the 3 values on the
75-g, 2-hour oral glucose tolerance test are associated with
graded increases in the likelihood of pregnancy outcomes
such as large for gestational age, cesarean section, fetal
insulin levels, and neonatal fat content. Based upon an
iterative process of decision making, a task force of the
International Association of Diabetes and Pregnancy
Study Groups(IADPSG) recommends that the diagnosis of
gestational diabetes be made when any of the following 3 75-
g, 2-hour oral glucose tolerance test thresholds are met or
exceeded: fasting 92 mg/dL, 1-hour 180 mg/dL, or 2 hours
153 mg/dL.

12. Criteria for the 2hour 75 g OGTT in
the diagnosis of GDM at 24-28
weeks
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IADPSG
mmol/liter
NICE
mmol/liter
fasting 5.1 (92mg/dl) > 5.6 (100 mg/dl) >
1 hour 10 (180 mg/dl) > ------
2 hour 8.5 (153 mg/dl) > 7.8 (140 mg/dl) >

13. Clinical features
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 GDM is usually asymptomatic and develops in
second and third triamester induced by
maternal changes in carbohydrate metabolism
and decreased insulin sensitivity.
 It may be diagnosed on routine investigation or
may be suspected in case of macrosomia
polyhydramnios , persistent heavy glucosuria,
recurrent infections.

14. Targets for daily capillary plasma
glucose
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 Fasting less than 5.3 mmol/liter ( 95 mg/dl)
 1 hour after meals less than 7.8 mmol/liter
(140 mg/dl)
 2 hours after meals less than 6.4 mmol/liter
(115mg/dl)

15. MANAGEMENT OF GDM
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 Women should be managed in a specialist
multidisciplinary diabetes pregnancy clinic.
 The mainstay of treatment is lifestyle advice
including dietary modification with reduced fat,
increased fiber and regulation of carbohydrate
intake.
 No excess risk of major malformations.
 After diagnosis women should be offered a
review in a joint diabetic antenatal clinic within
a week.

16. Management Of GDM
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 Women are at increased risk of preeclampsia
needs regular B.P and urinlysis for proteinuria.
 Women with a fasting plasma glucose at
diagnosis of less than 7mmol/liter(126 mg/dl)
should be offered diet and exercise as a method
of controlling blood glucose as long as there are
no other complications present such as
polyhydramnios and macrosomia. Regular daily
30 min of moderate exercise is encouraged.
 Blood glucose should be checked daily fasting
and one hour after meal.

17. Management Of GDM
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 If after 1-2 weeks of diet and exercise blood
glucose is not within these recommended
levels additional therapy should be offered.
 Pharmaocological treament with INSULIN and
METFORMIN will be required when diet and
exercise fails or woman develops
complications.

18. Recommended management of
GDM at diagnosis (NICE 2015)
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Fasting plasma
glucose mmol/l
at diagnosis
Complications Management Recommended
pattern of blood
glucose
monitoring
< 7 None 1-2 weeks tial diet
and exercise
Fasting + 1 hour
post meal daily
6.0-6.9 Polyhydramnios
macrosomia
Insulin +
Metformin in
addition to diet &
excercise
Oral therapy or
single dose
intermediate or
long acting
insulin.
> 7 Insulin +
Metformin in
addition to diet &
excercise
Multiple daily
insulin doses:
fasting, premeal,
post meal and

19. FETAL MONITORING
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 Regular ultrasound scans for growth liqour
volume and umblical artery Doppler at 4-
weekly intervals
 Fetal abdominal circumfernce to detect
macrosomia

20. TIME AND MODE OF
DELIVERY
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 Pregnant women with uncomplicated GDM be
offered elective birth no latter than 40 +6 weeks
gestation.
 Women with complications should be elecitvily
delivered before this gestation.
 Normal vaginal delivery is indicated and
operative delivery for other reasons and in
complications may be needed.

21. INTRAPARTUM CARE
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 Blood glucose should be checked every hour
in labour and levels should be maintained
between
4-7 mmol/liter (72-126 mg/dl)
 A sliding scale of intravenous insulin and
dextrose should be initiated if blood glucose
falls outside this range.
 Women who require steroid cover for lung
maturity should be treated in same way like
pre-existing diabetes.

22. POST NATAL CARE
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 GDM will not require any treatment after
delivery so all hypoglycemic treatment should
be discontinued.
 Pre-meal and bed time testing should be
continued until levels returns to normal (4-6
mmol/liter), then once daily while an inpatient.
 Contraception should be discussed prior to
discharge.
 Six week follow up with OGTT or FBS. Then
annual fasting blood glucose or HbAIc.

23. SUMMARY
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 GDM is the disease of second/third triamstar.
 Only at risk population is screened for GDM
 Maternal and fetal outcomes are same as
nondiabetics if glycemic control is kept under
targeted levels.
 Future development of diabetes type II is
higher so require annual screening.
 Recurrence risk is higher in subsequent
pregnancies.

24. 7/22/2018
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THANK YOU