1. GESTATIONAL DIABETES
MELLITUS
ANNABELLE MARIE
101303061
B27

2. INTRODUCTION
• 3-10% of pregnancies: abnormal maternal glucose
regulation
• 90% due to gestational diabetes mellitus
• Definition: glucose intolerance of variable degree with
onset or first recognition during pregnancy
• Rising prevalence of diabetes: women have some form
of diagnosed diabetes particularly type II DM among
women of childbearing age--- resulted in increasing
number of pregnant women with pre-existing diabetes
• Type II- 8% of cases of diabetes mellitus in pregnancy
and pre-existing diabetes mellitus now affects 1% of all
pregnancies.

3. Pathophysiology
• GDM characterised by hyperinsulinaemia and insulin
resistance resulting in abnormal carbohydrate
intolerance.
• In first trimester and early second trimester, increased
insulin sensitivity occurs due to relatively higher levels of
estrogen
• in late second and early third trimesters, increased
insulin resistance and rreduced sensitivity due to a
number of antagonistic hormones especially, placental
lactogen, leptin, progesterone, prolactin, cortisol and
adiponection

5. IMPLICATIONS OF DIABETES IN
PREGNANCY
DOUBLE risk of serious injury at birth
TRIPLE likelihood of Caesarean delivery
QUADRUPLE incidence of Neonatal
Intensive Care Unit admission

7. Effects of Pregnancy on Diabetes
• Difficult to stabilise blood glucose during pregnancy due
to altered carbohydrate metabolism and impaired insulin
action
• Insulin requirement increases as pregnancy advances
• Accelerated starvation----rapid activation of lipolysis with
short period of fasting
• Ketoacidosis can be precipitated durring
– hyperemesis gravidarum
– infection
– fasting of labour
– Iatrogenically induced by sympathomimetics and corticosteroids
used in preterm labour
• Accelerates vascular changes

8. EFFECTS OF DIABETES ON
PREGNANCY

9. Hyperglycaemia in 1st
trimester
Impaired
organogenesis
Congenital
abnormalities
Chronic maternal
hyperglycemia
Fetal
hyperinsulinaemia
Fetal hyperglycaemia
Increased fetal oxygen
demand
Glycosylated
Hb carries less
oxygen
molecule and
O2 binds more
avidly and
releases O2
less
Decreased Oxygen
tension (hypoxaemia)
Increase in anaerobic
metabolism
increased lactate and
acidaemia
Abortion/ IUD
Increased
erythropoiesis
Polcythaemia and
hyperviscosity
RBC breakdown and
neonatal
hyperbilirubinaemia

10. Maternal
hyperglycaemia
Fetal
hyperglycaemia
Fetal osmotic
diuresis
Polyhydramnios
Polyhydramnios
Fetal macrosomia
Fetal
hyperinsulinaemia
fetal hypoglycaemia
Increased IGF
Obstructed labour
Shoulder Dystocia
Erb's palsy/ Birth
Asphyxia
Decreased cortisol
production
Respiratory distress
syndrome
decreased
surfactant synthesis
in lung

11. Maternal Complications of GDM
During Pregnancy
Abortion
Preterm labour (due to infection or
polyhydramnios)
Pre-eclampsia
Polyhydramnios
Maternal distress due to oversized fetus and
polydramnios
Microangiopathy
Nephropathy, retinopathy, neuropathy
Large vessel disease
Coronary artery disease
Thromboembolic disease
Infection
Hypo and hyperglycaemia
During labour
Prolonged labour
Shoulder dystocia
Perineal injuries
PPH
Operative interference
Increased risk of Caesarean
delivery
Puerperium
Puerperal sepsis
Lactational failure

12. Fetal Complications
1st trimester
• Congenital
abnormalities
– Cardiac : ASD, VSD
– NTD
– Sacral agenesis/ CRS
– PCKD
– Renal agenesis
– Duodenal atresia
– Tracheoesophageal
fistula
2nd Trimester
• Macrosomia
Delivery
• Birth asphyxia
• Shoulder dystocia
After delivery
• RDS
• Hypoglycaemia
• Polycythaemia
• neonatal jaundice

13. Fetal and Neonatal Complications of
diabetes in pregnancy
• Shoulder dystocia leading to brachial plexus injury
and clavicular fracture---majority resolve and heal
within a few months

14. GESTATIONAL DIABETES PRE-EXISTING DIABETES
No increased risk of congenital
anomalies
increases risk of fetal macrosomia
Increases risk of having Caesarean
section
Increased risk for metabolic syndrome
and type II diabetes later in life (>50%
women with gestational diabetes
develop type II DM)
Babies born to women with gestation
diabetes are at inceased risk for obesity,
glucose intolerance and diabetes in
adolescence
Higher risk of congenital
malformations and miscarriages
Recurrent urinary tract infections
Vulvovaginal infections with poor control
Associated with risk of (PPPPRIM)
Pre-eclampsia,
Polyhydraminos,
PPROM,
Preterm labour,
Risk of operative deliveries
IUGR
Macrosomia
Ketoacidosis in type I, progression of
microvascular complications
Caesarean section rates invariably
increased due to fetal macrosomia, poor
blood sugar control, polyhydramnios or
associated with failure of induction

15. Risk Factors
• Age >25years
• BMI >25kg/m²
• Increased weight gain
during pregnancy
• Previous history of large
for gestational age infants
• History of GDM during
previous pregnancies
• previous stillbirth with
pancreatic islet
hyperplasia on autopsy
• Ethnic group ( East
Asian, Pacific Island
ancestry)
• Elevated fasting or
random blood glucose
levels during pregnancy
• Family history of diabetes
in first degree relatives
• History of metabolic X
syndrome
• History of type I or type II
Diabetes Mellitus
• Unexplained fetal loss

16. Signs
Elevated serum glucose:
severely elevated blood glucose
level on random glucose testing
excludes the need for screening
GLycosuria is od uncertain
significance during pregnancy
Ketonuria
Elevated glycosylated
haemoglobin
Ultrasound features such as
greater than normal abdominal
circumference
DIAGNOSIS
Symptoms
Asymtomatic
Insidious onset
Polyuria, polyuria,
polyphagia
Vague symptoms of fatige
and abdominal discomfort and
weight loss
Women with established
diabetes may have symptoms
such as retinopathy or
neuropathy

17. SCREENING AND DIAGNOSTIC
INVESTIGATION
• NORMAL
• Random blood glucose level 11.1mmol/L
• Fasting blood glucose level 7.0mmol/L
• ABNORMAL
• Random bood glucose level ≥ 11.1mmol/L
• Fasting blood glucose level ≥ 7.0mmol/L

18. Glucose Challenge test
• 24-28 weeks gestation
• 50g glucose drink given to the patient and blood
is drawn after 1 hour to measure blood glucose
levels
• of the test result is positive i.e blood glucose
level ≥ 7.2mmol/L (some clinicians use cut off
as 7.8mmol/L), then the patient has to undergo
the 3 hour 100g oral glucose tolerance test
Normal
Serum or plasma glucose level 7.2mmol/L
Some clinician use a cut off of 7.8mmol/L
Abnormal
Serum or plasma glucose level ≥ 7.2mmol/L or ≥ 7.8mmol/L

19. • Advantages
• 2 step approach
identifies
approximately 80% of
women with
gestational diabetes
using of 7.8mmol/L
and approximately
90% women with cut
off 7.2mmol/L
• Disadvantages
• False positives
common
• Sensitivity of Glucose
tolerance screening
varies with patient
ethnicity

20. Indications
• Glycosuria on one occasion before 20th week and
• 2 or more occasions thereafter
• Glycosuria occuring at anytime during pregnancy with
• a positive family history of diabetes or past history of
having a baby 4kg or more.
• Following positive screening test
• If FBG is more than 126mg/dL and if confirmed on
repeat testing, there is no need to do MGTT

21. 75g Oral Glucose Tolerance test- Modified
Oral Glucose Tolerance (MGTT)
• Patient consume at least 150g carbohydrate for 3 days
prior to test
• Patient should rest, no smoking, no drugs, no signs and
symptoms of infection
• Fasting for 12hours is recommended and maternal
venous blood is drawn to measure the fasting blood
glucose level
• A 75g glucose in 300ml drink is given to the patient and
blood is drawn at intervals to measure glucose levels.
• Only a fasting and 120min sample are needed

22. WHO Croteria for 2 hours 75g glucose
tolerance test
whole blood
venous
(mmol/L)
whole blood
capillary
(mmol/L)
Plasma venous
(mmol/L)
Plasma
capillary
(mmol/L)
Fasting >6.1 >6.1 >7.0 >7.1
2hrs >6.7 >7.8 >7.8 >8.9
Category Normal IGT Diabetes
Mellitus
Fasting <5.6 5.6-7.8 >7.8
2hrs <7.8 7.8-11.1 >11.1

23. Other Screening Tests
Glycosylated haemoglobin
• Blood sample
• Reflection f patients glycaemic control over the previous
2-3 months
• Ordinarily decreased during pregnancy
• Risk of fetal malforrmation correlates with degree of
hyperglycaemia during the first 6-8 weeks of gestation if
HbA1c is 1% or more above normal
• Normal: 4.7-6.3% in non pregnant women,
4.5-5.7% in pregnant women
4.4-5.6% in late pregnancy
Advantage: does not require fasting plasma glucose

24. PRINCIPLES OF
MANAGEMENT

25. Antenatal care
• All diabetic women are managed in a multidisciplinary
combined obstetric and diabetic clinic with specialist
obstetrician, diabetologist, specialist midwife,
paediatrician and dietician
• All women should recieve dietary instruction, with
individual recommendations based on weight and height
• Patient should recieve nutrition counselling from a
registered dietician
• Daily calories should be made up approximately 40%
carbohydrate, 20% proteins and 40% fats.
• This should improve blood glucose levels

26. Antenatal Care
Multidisciplinary
approach
Dietary instruction
with individual
instruction based
on height and
weight
Nutrition
counselling from
registered dietician
Daily calories
should be made up
approximately 40%
carbohydrate, 20%
proteins and 40%
fats.
A daily intake of 2000
to 2200 :
30 kcal/kg for women
with an ideal
prepregnancy weight
In women who are
obese (BMI:
>30kg/m²), calorie
reduction by
approximately one
third (to approximately
25kcal/kg/d) may be
acceptable, although
caloric restriction
during pregnancy
must be viewed with
caution.
Non caloric
sweetener used in
moderation
Increased fibre
intake for
constipation
Vitamins and
supplements
Avoid alcohol
Moderate exercise

27. Role of Ultrasound
• Preferably done in first trimester to confirm gestational
age by dates
• Repeated at 18 to 20 weeks gestation to evaluate the
fetus for congenital anomalies
• Particularly important in patients with pre-existing type 1
and 2 diabetes and elvated first trimester HbA1c (>6.5%)
• Should be done at 30 to 32 weeks and 36-38 weeks of
gestation to evaluate fetal size, amniotic fluid index, and
to hlp ascertain the mode of delivery

28. Tests of fetal wellbeing
• Daily fetal movement counting: 32
weeks gestation and continue until
delivery
• Amniotic fluid index and biophysical
profile:
– these tests are usually conducted twice
weekly and are institued at 32 to 34 weeks
of gestation in women on insulin and can be
done from 34-36 weeks of gestation in
women whose diabetes is controlled by diet
– Some clinician mahe patients with diet
controlled gestational diabetes as they
would a patient with a normal pregnancy
without any additional testing.

29. Blood glucose monitoring
• Maternal metabolic surveillance should
be directed at maintaining glycaemic
control and detecting
hyperglycaemia
• Target for blood glucose levels are
usually
• 5.6mmol/L for fasting blood glucose
• 7.2mmol/L for 1hr postprandial blood
glucose or
• 6.7mmol/L for 2hr postprandial blood
glucose to reduce macrosomia
• Ideally daily self monitoring of blood
glucose four times daily is
recommended to establish glycaemic
control. However in practice it is done
fortnightly

30. • In patients requiring insulin therapy, glucose
levels should be checked at least 4 times a day
• a glucose level measured first thing in the
morning can rule out fasting hyperglycaemia and
additional 1 or 2 hour postprandial values can
ensure adequate glycaemic control
• In patients with diet controlled gestational
diabetes, testing 4 times daily may be done
once a fortnight
• Urine ketones need to be checked periodically
during pregnancy

31. SUMMARY
Diagnosis
Consult about diet and lifestyle
Do blood sugar profile after 1-2
weeks
If range between 4-7 mmol/l
consider diet therapy
If >7mmol/l or type 1 diabetes or
U/S show fetal macrosomia,
start insulin (actrapid 4-6U
tds). Can admit patient for
education therapy
Antenatal visit fortnightly till 32
weeks, weekly after 32 weeks
During check up, monitor BSP
and detect any complications
of DM
Fetus: 11-14weeks correct
dating
Morphological scanning in 2nd
trimester between 18-
22weeks
Serial scan for big baby, IUD,
polyhydramnios
(accelerated growth rate of
abdominal circumference
indicate macrosomia
HbA1c should check for every
trimester (especially 1st
trimester) Maintain below 7%
Check for urinary tract infection
and vaginal candidiasis

32. MEDICATIONS AND
OTHER THERAPIES

33. • Human insulin is treatment of choice when blood
glucose is not adequately controlled by diet
• Insulin therapy is indicated when diet does not
maintain blood glucose levels at 5.8mmol/L for fasting
blood glucose, 8.6mmol/L for 1 hr or 7.2mmol/L for
2hour postprandial blood glucose (Obs today)
• Insulin therapy also recommended if blood glucose
levels are not controlled adequately by diet alone after
two week trial

34. • Regular insulin is the preferred short
acting insulin for pregnant patients.
• NPH insulin is the preferred
intermediate acting insulin for pregnant
patients
• Therapy is based preferably by self
monitoring of blood glucose levels
• A patient newly started on insulin will
begin at doses of 50-75% of the
calculated dose
• Insulin dose should be individualised
and adjusted according to the patient's
blood glucose levels
Give actrapid 4-6U
TDS
Monitor for 2 weeks
If still elevated
increase until 12 U
tds
If still cannot control
add intermittent
acting insulin
(monotard)
If total of >30U per
day, it indicate
moderate-severe
poor control of DM.

35. Adverse effects
• Hypoglycaemia
• Lipoatrophy or lipohypertrophy
• Flushing
• Rash
• Urticaria
• Acute edema
• Hepatomegaly in high doses

36. Sulfonylureas
Insulin secretagogues
GLipizide, glyburide
Increase insulin
secretion, decrease
hepatic glucose
production with
resultant reversal or
hyperglycaemia and
indirect improvement of
insulin sensitivity
Meglitinides
Biguanides
Decrease insulin
resistance
Alpha glucosidase
inhibitors eg acarbose)
decrease intestinal
absorption of starch and
glucose
Thiazolidinediones
Eg rosiglitazone and
pioglitazone

37. Oral Antidiabetic agents
• Has not been recommende in the part because of
concerns of potential teratogenicity and transport of
glucose across the placenta
• Glyburide: does not cross the placenta in significant
amounts and recent trials have said it is safe to use
• American College of Obstetricians and Gynecologists
and ADA recommend not to prescribe it until further
studies support its safetly and efficacy
• Include: Sulfonyl ureas (insulin secretagogues)

38. Time and mode of delivery
• All pregnant women advised during the antenatal care about
the potential risks of pregnancy progressing beyond term
• Gestational diabetes
– GDM on diet with no complications can be delivered at 40 weeks
– GDM on insulin should be delivered by induction of labour at 38-39
weeks
• Pre-existing diabetes
– Diabetes itself not an indication for Caesarean Section
– Pregnant women with diabetes who have a normally grown fetus should
be offered elective birth through induction of labour, or by elective
caesarean if indicated, after 38 completed weeks
– Pregnant women with ultrasound features of macrosomic fetus (fetal
weight more than 4.5kg) and poorly controlled blood sugar are
delivered by elective caesarean section.

39. Diabetes and C-section
• Preoperative considerations
• Patient should take their evening dose of NPH insulin the
night before the procedure
• Do not take the morning dose of insulin
• If necessary, intravenous insulin infusion can be aded to
maintain normoglycaemia

40. • Intraoperative consideration
• Maintain normoglycaemia
• Postoperative considerations:
• Reassess glycaemic control after delivery

41. • Postpartum Management
• Blood glucose levels usually decline rapidly after delivery
• Blood glucose levels should be reassessed at 6 weeks after
delivery, if not before, an then at 3 year intervals if levels are normal.
• If impaired fasting glucose or impaired glucose tolerance are
observed postpartum, the patient should be tested annually for
diabetes.
• All women with gestational diabetes should be counselled regarding
diet, weight loss (if needed), and exercise in order to decrease the
longterm risk of type 2
• patient with pre-existing diabetes should be transitioned to
appropriate treatment postpartum (eg oral agent or adjusted insulin
dosage)
• Contraception

42. • After 6 weeks or more following delivery, can diagnose
Diabetes Mellitus if symptoms of diabetes mellitus are
present
Random blood glucose 11.1mmol/L
Fasting blood glucose 7.0mmol/L
2hour post prandial 75g glucose
tolerance test
11.1mmol/L

43. Resources
• Obstetrics Today- 2nd edition Prof Sachichitanantham
and Dr Kavitha Nagandla
• DC Dutta
• Medscape