1) Gestational diabetes mellitus (GDM) is a form of diabetes diagnosed during pregnancy that is not clearly type 1 or type 2 diabetes. It results from the body's inability to produce enough insulin or use it effectively, and puts both mother and baby at risk. 2) GDM is tested for between 24-28 weeks of gestation using a glucose challenge test and potentially an oral glucose tolerance test. It is treated through diet, exercise, blood glucose monitoring, and potentially insulin. 3) Both mother and baby can experience risks if GDM is not managed well, such as preeclampsia, macrosomia, and long-term metabolic disorders. Ongoing screening is important after pregnancy to

1. Dr Shahjada Selim
Assistant Professor
Department of Endocrinology
Bangabandhu Sheikh Mujib Medical University, Dhaka
Email: selimshahjada@gmail.com, info@shahjadaselim.com

2. Gestational diabetes mellitus (GDM):
Diabetes diagnosed in the second or third
trimester of pregnancy that is not clearly
overt diabetes.
(American Diabetes Association, 2017)

3. *3 to 15% of all pregnancies are complicated
by diabetes
*0.2% to 0.5% of all pregnancies occur in
women with pre-existing diagnosis of type 1
DM
*similar number has pre-existing type 2 DM

4. *Early in pregnancy, maternal estrogen and
progesterone increase and promote pancreatic ß-
cell hyperplasia and increased insulin release
*As pregnancy progresses, increased levels of human
placental lactogen, cortisol, prolactin,
progesterone, and estrogen lead to insulin
resistance in peripheral tissues.

5. *Table 1 describes the diabetogenic potency
and time of peak effect of these hormones.
The timing of these hormonal events is
important in regard to scheduling testing for
GDM

7. *GDM results when there is delayed or insufficient insulin secretion in the
presence of increasing peripheral resistance

8. Increased lipolysis
 Mother uses fat for her caloric needs & serves
glucose for fetal needs
 Changes of gluconeogenesis
 Fetus preferentially utilizes alanine & other
amino acids deprivng the mother of major
neoglucogenic source

9. *Test for undiagnosed T2DM at the 1st
prenatal visit in those with risk factors. B
*Test for GDM at 24–28 weeks of gestation in
women not previously known to have
diabetes. A
*Screen women with GDM for persistent
diabetes at 4–12 weeks postpartum, using
the OGTT. E
American Diabetes Association Standards of Medical Care in Diabetes.
Classification and diagnosis of diabetes. Diabetes Care 2016; 39 (Suppl. 1): S13-S22

10. *If GDM is not Dx. repeated at 24-28
wks or at any time a pt. has a
symtoms or signs suggestive of
hyperglycemia

11. *Women with GDM history should have lifelong
screening for development of diabetes or
prediabetes at least every 3 years. B
*Women with GDM history found to have prediabetes
should receive lifestyle interventions or metformin
to prevent diabetes. A
American Diabetes Association Standards of Medical Care in Diabetes.
Classification and diagnosis of diabetes. Diabetes Care 2016; 39 (Suppl. 1): S13-S22

12. Low risk status:
 Age<25 years
 Weight normal before pregnancy
 Member of an ethnic group with low prevalence
of GDM
 No first degree relative of DM
 No H/O abnormal glucose tolerance
 No H/O poor obstetric outcome

13. High risk status:
Obesity
Advanced maternal age, >25 yrs
Asian origin irrespective of age
Previous H/O DM or abnormal glucose tolerance
Glycosuria
H/O poor obstetric outcome
``

14. *At 24-28 weeks gestation in women not previously dx’d
with overt diabetes
*75-g OGTT; Measure plasma glucose at fasting and at 1
and 2 hours.
*GDM dx’d when plasma glucose exceeds:
*Fasting: 92 mg/dL (5.1 mmol/L)
*1 h: 180 mg/dL (10.0 mmol/L)
*2 h: 153 mg/dL (8.5 mmol/L)
American Diabetes Association Standards of Medical Care in Diabetes.
Classification and diagnosis of diabetes. Diabetes Care 2016; 39 (Suppl. 1): S13-S22

15. Step 1:
* In women not previously dx’d with overt diabetes,
perform 50-g GLT (nonfasting); Measure plasma
glucose at 1 hour.
* If 1 hour plasma glucose level is ≥140 mg/dL* (7.8
mmol/L), proceed to step 2.
*ACOG recommends 135 mg/dL in high-risk ethnic
minorities with higher prevalence of GDM.
American Diabetes Association Standards of Medical Care in Diabetes.
Classification and diagnosis of diabetes. Diabetes Care 2016; 39 (Suppl. 1): S13-S22

16. Step 2: 100-g OGTT is performed while patient is fasting. The
diagnosis of GDM is made if 2 or more of the following plasma
glucose levels are met or exceeded:
American Diabetes Association Standards of Medical Care in Diabetes.
Classification and diagnosis of diabetes. Diabetes Care 2016; 39 (Suppl. 1): S13-S22
Carpenter/Coustan or NDDG
Fasting 95 mg/dL (5.3 mmol/L) 105 mg/dL (5.8 mmol/L)
1h 180 md/dL (10.0 mmol/L) 190 mg/dL (10.6 mmol/L)
2h 155 mg/dL (8.6 mmol/L) 165 mg/dL (9.2 mmol/L)
3h 140 mg/dL (7.8 mmol/L) 145 mg/dL (8.0 mmol/L)

17. Maternal effect:
 Associated with poor glycaemic control
 Increased maternal mortality
 Preeclamsia
 Birth canal trauma
 Long term- Metabolic syndrome
 Increased CVS risk


18. Fetal Effect:
Fetal Macrosomia
Still birth
Birth injury
Long term- obesity and DM in offspring
Hypoglycemia
Hyperbilirubinemia

19. Dietary Therapy
Exercise
Self BG monitoring
Administration of Insulin if target blood glucose
level are not met by diet alone
Fetal surveillance
Intrapartum care
Post partum care

20. Nutritional counseling by a registered nutritionist upon
diagnosis
The goals of Medical nutritional therapy are to:
Achieve normoglycemia
Prevent ketosis
Provide adequate weight gain
Maintain fetal well being
Prevent hypoglycemia
Two weeks for diet therapy

21. Nutritional therapy: cont.
The major components to consider when creating a nutritional
plan for women with GDM are calorie allotment, carbohydrate
intake and calorie distribution.
Callorie allotment is based upon ideal body weight. The
suggested calorie intake is approx:-
30 kcal per kg current weight per day in pregnant women
who are BMI 22-27
24 kcal per kg per for BMI of 27-29
12-15 kcal per kg for BMI of > 30
40 kcal per kg for BMI < 22

22. Calorie intake:
CHO-55%
Protein-20%
Fat-25%
With this calorie distribution, 70 to 80% of women
with GDM will achieve euglycemia
Calorie distribution:
3 meal
3 snacks
however in overweight and obese women the snacks
are eliminated.
Nutritional Therapy: cont.

23. Improves Insulin sensitivity
Upper extremity exercise
Moderate physical activity with no medical or
obstetrical contraindication

24. SMBG (daily self monitoring of blood glucose)
superior to intermittent office monitoring
Blood glucose report should be written in a glucose
dairy
Blood glucose measured 4 times a day- On awakening,
1-2 hrs after each meal
Hba1c is a helpful ancillary test
Should be checked at 4 weeks interval

25. Recommendations for starting Insulin: (ADA guideline)
FPG> 5.8mmol/l or
1 hr PG> 8.6 mmol/l
2hr PG > 7.2 mmol/l
Target blood glucose:
Pre prandial <5.3mmol/l
1 hr post prandial <7.8 mmol/l
2 hr post prandial <6.7 mmol/l

26. Calculating dose:
Total insulin- 20-30 U/day
2/3rd
intermediate acting (NPH)
1/3rd
regular Insulin
Calculated daily dose of insulin:
1st
trimester-0.8 unit ×kg BW
2nd
trimester- 1 unit ×kg BW
3rd
trimester- 1.3 unit×kg BW

27. The dose and type of insulin used is calculated
according to the blood glucose level
If the FBG is high then, an intermediate- acting
insulin, is given before bedtime.
If postprandial blood glucose levels are high, then
regular rapid-acting insulin are added before meals.
Insulin Therapy cont.

28. If both preprandial and postprandial blood glucose levels are
high,then initiate a four injection per day regimen.
The insulin is divided according to the following schedule: 45%
as NPH insulin(30% before breakfast & 15% before dinner) and
55% as preprandial regular insulin(22% before breakfast,18%
before lunch and 14% before dinner).
A four-times daily regimen improved glycemic control and
prenatal outcome compared to a twice- daily regimen.
Insulin Therapy cont.

29. Regular Insulin is withheld during labor ; a sliding scale of
soluble insulin should be started (or infusion pump as may
be fit)
Maternal hyperglycemia should be avoided during labor to
prevent fetal hyperinsulinemia and subsequent neonatal
hypoglycemia
Maternal blood glucose should be maintained between 4- 5
mmol/L.
Peripartum MX:

30. Blood glucose should be measured on the day after
delivery to using criteria established for nonpregnant
women.
A women with GDM should be able to resume a regular
diet postpartum.
Screen women with GDM for persistent DM 6-12 weeks
post partum
Lifelong screening at list every 3 years
Peripartum MX: cont.

31. Nearly all women(90%) with GDM are normoglycemic
after delivery. However they are at risk for recurrent GDM,
impaired glucose tolerance and overt diabetes.
2/3rd
of women with GDM will have GDM in a subsequent
pregnancy.
Future Risk:

32. Should be consulted with health care provider
Glucose tolerance test should be done prior to
conception

33.  GDM offers an important opportunity for the
development, testing and implementation of clinical
strategies for diabetes prevention.
 Screening all pregnant women, achieving
euglycemia in them and ensuring adequate nutrition
may interrupt the vicious cycle of glucose intolerance
from one generation to another.