This document discusses gestational diabetes, including its definition, epidemiology, consequences for both mother and fetus, screening recommendations, management, and controversies around diagnostic criteria. Some key points: - Gestational diabetes is defined as carbohydrate intolerance first recognized during pregnancy and can include undiagnosed preexisting diabetes. - It affects 2-9% of pregnancies and screening is recommended for at-risk women between 24-28 weeks using a 75g oral glucose tolerance test. - Risks for the fetus include macrosomia, jaundice, and hypoglycemia. Risks for the mother include preeclampsia, infections, and long-term risk of type 2 diabetes.

1. Gestational Diabetes
To Change or Not to Change
Lobna Farag Eltoony
Head of diabetes and Endocrinology Unit
Department Of Internal Medicine
Assuit University

2. Agenda
Definition
Epidemiology
The fetal and maternal consequences of
GDM and pregestational diabetes.
Preconception care
The evolution of a diagnostic controversy
Screening : Who? Why? When? How?
Management

3. Diabetes and pregnancy
One of the most challenging aspects of
diabetes practice
Seemingly easy: Practically difficult
Needs a lot of commitment on part of
doctor, patient and family
Success can be achieved if we try
together
Let’s begin by staying awake
for the next 20 minutes

4. Gestational diabetes
Definition
Carbohydate intolerance of variable
severity first recognised during the
present pregnancy.
This includes women with preexisting but
previously unrecognised diabetes.

5. Gestational diabetes
Incidence
2-9%
more common in Asian and Indian
women . In developed countries,
increasing trend because of epidemic of
obesity and T2DM.

6. Epidemiology
Most common medical complication of
Pregnancy
affects 8% of pregnancies
Gestational DM 90% Diabetes 8%
Preexisting DM 10% 6
Nondiabetes
92%
Diabetes8%
24%
Diagnosed
T2DM
50%GDM

7. Diabetes in pregnancy
Pre-existing diabetes Gestational diabetes
Pre-existing diabetes
IDDM
(Type1)
NIDDM
(Type2) True GDM

8. Pregestational Diabetes
In our practice , many women who are
first diagnosed with diabetes mellitus
during pregnancy are classified as having
gestational diabetes even though they
have pre-existing, or pregestational,
diabetes that had gone undiagnosed.

9. Pregestational vs Gestational
Diabetes
This distinction is crucial because
pregestational diabetes is associated
with more serious consequences for the
fetus than is diabetes in the second and
third trimester of pregnancy.
(A wolf in sheep’s clothing).

10. Pregestational Diabetes
Women with pregestational diabetes
who become pregnant are at increased
risk of giving birth to a baby with a
serious birth defect, including cardiac,
neurological, and vascular anomalies.
Reece et al 2009 lancet

11. Diabetes and pregnancy
Placental structure and
function is affected
Early IUGR as high BG
inhibits trophoblast
proliferation
Hypertension, renal
disease more frequent
High glycogen content in
placenta

12. Complications of pregnancy in pre-
existing DM
Maternal:
Increase insulin requirment’
Hypoglycemia
Infection
Ketoacidosis
Deterioration in retinopathy’
Increased proteinuria+edema
Miscarriage
Polyhydramnio
Shoulder dystocia
Preeclampsia
Increased caesarean rate
Fetal:
Congenital abnormalities
Increased neonatal and perinatal mortality
Macrosomia
Late stillbirth
Neonatal hypoglycemia
Polycythemia
jaundice

13. Caudal regression syndrome
(abnormal development of lower spine )

14. Teratogen Period of
exposure
Complications
Type of
Diabetes
Aberrant
fuel mixture
Hyperinsulinaemia
Foetus
delivery
G
D
M
P
G
D
M
1st trimester
2nd trimester
3rd trimester
Spontaneous abortions
Early growth delay
Congenital anomalies
Macrosomia
Selective
Organomegaly
CNS development
delay
Chronic hypoxia
Stillbirth
Birth injury

15. Fetal
hyperinsulinemia
The Impact of Maternal Hyperglycemia
During Pregnancy
Modified Pedersen Hypothesis
Fetus
Fetal pancreas stimulated
IgG=immunoglobulin
G
Mother
Placenta
IgG-antibody-bound
insulin
Insulin
Maternal hyperglycemia
Insulin resistance syndrome

16. Maternal hyperglycemia
Fetal hyperglycemia
Fetal hyperinsulinemia
Pederson
Hypothesis
(1952)
Macrosomia,organomegaly, polycythaemia,
hypoglycemia, RDS
Pathogenesis of Gestational diabetes

17. Neonate
Child
Adult
RDS
Hypoglycemia
Hypocalcemia
Hypomagnesemia
Thrombocytopenia
Polycythemia
heel-stick blood
Renal vein
thrombosis
Hyperbilirubinemia
Behavior - Intellect deficit
Obesity
Diabetes mellitus

18. Growth Abnormalities(1)
Two Extremes Of Growth Abn:

19. Before conception is attempted, A1C levels
Close to normal as possible (<7%) (B)
Starting at puberty
Incorporate preconception counseling in routine
diabetes clinic visit for all women of child-bearing
potential (C)
Evaluate women contemplating pregnancy; if
indicated, treat for
Diabetic retinopathy
Nephropathy
Neuropathy
CVD (E)
Recommendations:
Preconception Care (1)
ADA. VII. Diabetes Care in Specific Populations. Diabetes Care. 2011;34(suppl 1):S41.

20. Evaluate medications used prior to conception
Drugs commonly used to treat diabetes,
complications may be contraindicated or not
recommended in pregnancy, including
Statins, ACE inhibitors, ARBs, most noninsulin
therapies (E)
Since many pregnancies are unplanned, consider
potential risks/benefits of medications
contraindicated in pregnancy in all women of
childbearing potential; counsel accordingly (E)
ADA. VII. Diabetes Care in Specific Populations. Diabetes Care. 2011;34(su
Recommendations:
Preconception Care (2)

21. Gestational Diabetes
Fetal Risks
Macrosomia - shoulder dystocia and related complications
Jaundice
Hypoglycemia
No increase in congenital anomalies
Exposure to GDM in utero
LGA children or those born to obese mother have a 7% risk of
developing IGT at 7-11 yrs age
Breastfeeding may lower risk
CDA CPG 2008

22.  Pre-eclampsia: affects 10-25% of all pregnant women with
GDM
 Infections: high incidence of chorioamnionitis and postpartum
endometritis
 Postpartum bleeding:
 Cesarian section more common due to fetal macrosmia and
cephalo-pelvic disproportion
 Weight gain
 Hypertension
 Miscarriages
Third trimester fetal deaths
 Long term risk of type-2 DM (40-60%) of within10-15 yr.
Effects of GDM on the mother

24. DETECTION AND DIAGNOSIS OF
GESTATIONAL DIABETES
MELLITUS

25. Screening Tests for GDM
Best method still
controversial

26. NO CONSENSUS ON GDM
SCREENING
Why? When? Who? How?

27. WHY?
•Increased risk of perinatal morbidity : Macrosomia’
Shoulder Dystocia ,Birth injuries and Hypoglycemia
Treatment reduces perinatal morbidity
Increased risk of maternal morbidity :Preeclampsia
Cesearean Section , Pregnancy-induced hypertension and
Type2 diabetes mellitus
Treatment reduces maternal morbidity ,
Landon et al NEJM 2009;

28. Screen for undiagnosed type 2 diabetes at the
• first prenatal visit in those with risk factors, using
standard diagnostic criteria (B)
In pregnant women not previously known to have
diabetes, screen for GDM at 24-28 weeks gestation,
using a 75-g OGTT
Recommendations:
Detection and Diagnosis of GDM (1)
WHEN?
ADA. III. Detection and Diagnosis of GDM. Diabetes Care 2011;34(suppl 1):S15.

29. Risks for developing gestational
diabetes
WHO?
Aged 35 or over
Overweight BMI > 25
Positive FH of type 2 diabetes
Previous unexplained stillbirth, foetal malformation
or large baby (>4.5kg)
Persistent fasting glycosuria
More than 3 previous children
polyhydramnios
Diagnosis of PCOS ADA 2011

30. The evolution of a diagnostic
controversy
How?
1 hr 50 g OGTT.
2 hr 75 g oral OGTT
3 hr 100 g OGTT

31. Gestational Diabetes (GDM)
The American Congress of Obstetricians and
Gynecologists (ACOG),endorses the older 1997 criteria,
which involve a 2-step process:
Step 1: Screening 1 hr 50 g
OGTT. If PG >140 mg/dL,
proceed to Step 2.
Step 2: 3 hr 100 g OGTT
Fasting ≥95 mg/dL
1 hr ≥180 mg/dL
2 hr ≥155 mg/dL
3 hr ≥140 mg/dL

32. To Be or Not To Be , that is the question.
To Change or Not To Change .

33. Gestational Diabetes (GDM)
In 2011, the ADA affirmed the recommendations of the
International Association of Diabetes and Pregnancy Study Groups
(IADPSG),based on the results of the Hyperglycemia and Adverse
Pregnancy Outcomes (HAPO) study. Its current universal screening
test is the
75 g oral OGTT, with measurement of plasma glucose (PG) over2
hr. The test is performed at 24–28 weeks of gestation, after an
overnight fast of at least 8 hr. The diagnosis of GDM is made when
Any one of the following PG values is
Fasting ≥92 mg/dL
1 hr ≥180 mg/dL
2 hr ≥153 mg/dL
Diabetes Care 34:Supplement 1, 2011
Diabetes Care 2010; 33: 676–682

34.  These new criteria will significantly increase the prevalence of
GDM, primarily because only one abnormal value, not two, is
sufficient to make the diagnosis.
The ADA recognizes the anticipated significant increase in the
incidence of GDM to be diagnosed by these criteria and is
sensitive to concerns about the “medicalization”
of pregnancies previously categorized as normal. These
diagnostic criteria changes are being made in the context of
worrisome worldwide increases in obesity and diabetes rates,
with the intent of optimizing gestational outcomes for women
and their babies.
Screening for and Diagnosis of GDM

35. Although the anticipated benefits include
decreased rates of maternal and offspring
obesity, metabolic syndrome, and diabetes, it
is not yet clear how these benefits can be
achieved in an environment of significantly
restricted health care resources.
In addition, a dramatic increase in the rate of
cesarean deliveries, the benefits of better
diagnosis may be offset by increased cesarean
delivery– related complications and costs.
The evolution of a diagnostic
controversy

36. Disclosure
None ...
Where guidelines disagreed, I
picked the one I agreed with ☺

37. Screen women with GDM for persistent diabetes
6-12 weeks postpartum (E)
Women with a history of GDM should have lifelong
screening for the development of diabetes or
prediabetes at least
every three years (E)
Recommendations:
Detection and Diagnosis of GDM (2)
ADA. III. Detection and Diagnosis of GDM. Diabetes Care 2011;34(suppl 1):S15.

38. Postpartum Care-cont:
Follow up:
Per American Diabetes Association, a 75 g two
hours oral GTT should be performed 6-8 wks
after delivery.

39. Normal glucose tolerance 5
Impaired glucose tolerance 3
Diabetes mellitus 1
1/9
5/93/9
Normal glucose tolerance Impaired glucose tolerance Diabetes mellitus
Post partum follow up at 6 weeks

40. Gestational diabetes
Management
Management similar as preexisting DM
Need for glucose monitoring
Start with Diet control
Commence insulin for poor control
Delivery plan individualised

41. Target Blood Glucose Values
for GDM
Glucose level
Fasting - 90-99 mg/dL (5.0–5.5 mmol/L)
1- hr PP - < 140 mg/dL (7.8 mmol/L)
2- hr PP - < 120-127 mg/dL (6.7–7.1 mmol/L)
• HbA1c should not be used routinely for
assessing glycemic control in the second and
third trimesters of pregnancy.”NICE 2008
Fifth International Workshop Conference on Gestational Diabetes

42. Medical Nutrition Therapy
Low-carbohydrate diet , high fibre with
caloric restriction
Frequent small snacks may be needed
between meals
Avoid starvation

43. Medical Nutrition Therapy
Monitor urine ketones before breakfast
to detect starvation ketonuria
3 meals and 3 snacks
50-60% complex high fiber
carbohydrates
18-20% protein or at least 75 g
<30% fats
ASGODIP 1996

44. INSULIN
MEDICATION
ORAL DRUGS

45. Consider insulin
when ...
Diet and exercise fail to maintain glucose
targets during a period of 1-2 weeks
Ultrasound suggests incipient fetal
macrosomia (AC >70th percentile)
NICE 2008

46. Insulin remains the agent of choice
“In poorly resourced areas
of the world,
The theoretical disadvantages
of using oral glucose lowering
agents ... far less than the risks of non
treatment.”
IDF 2011
Consider insulin
when ...

47. Recommended
insulin regimens?
Initiate a basal-bolus regimen if a patient
cannot maintain glucose targets with
diet alone.
NPH insulin (basal) and rapid-acting
insulin at meals
Subcutaneous insulin infusion with an
insulin pump
AACE 2007

48. Which type of insulin and which
regimen?.
Insulin Analogues
1. rapid-acting insulin analogs
(lispro and aspart ) Cat B
concerns about teratogenesis, antibodies formation,
growth-promoting properties
majority of evidence showed that it does
not cross placenta, and has no adverse
maternal or fetal effects

49. Aspart, Lispro: category B
Regular insulin: category B
Glargine, Detemir: category C
Insulin Analogues

50. Insulin therapy
in GDM
Initiating dose depends on the blood
glucose
May start daily insulin dose
0.1-1.0 u/kg BW
ASGODIP 1996
Multidose Insulin
breakfast 25% H
lunch 15% H
supper 25% H
hs 35% NPH
indicates insulin as a % of total
daily dose

51. Gestational Diabetes
If persistent hyperglycemia after one
week of diet control proceed to insulin
6-14 weeks 0.5u/kg/day
14-26 weeks 0.7u/kg/day
26-36 weeks 0.9u/kg/day
36-40weeks 1 u /kg/day
53

52. Oral Hypoglycemic agents
Implicated as teratogeneic in animal
studies esp first generation sulfonyureas
In humans, scattered case reports of
congenital abnormality
Risk of congenital abnormality related to
maternal glycemic control rather than
mode of the anti-DM agents

53. Option of giving metformin or
glibenclamide
“Obtain and document informed
consent.
... tailored to glycemic profile of, and
acceptability to, the individual woman.”
NICE 2008

54. Alternative to Insulin Therapy
Metformin:
Cat B drug
Commonly used in Polycystic Ovarian Disease (PCOD)
to treat insulin resistance and normalize
reproductive function
Not teratogeneic
Reduce first trimester miscarriage
10X reduce gestational diabetes
Glueck, Fertil Steril 2002
Reece, Curr Opin Endocrinol Diabetes, 2006
Hague, BMJ, 2003
Glueck, Human Reprod, 2004

55. Metformin and Pregnancy
Rowan et al. New Engl J Med 2008; 358: 2003 - 15

56. Metformin and Gestational
Diabetes
Rowan et al. New Engl J Med 2008; 358: 2003 - 15
Mother and Child are okay

57. Metformin for the Treatment of
GDM
In women with gestational diabetes mellitus,
metformin (alone or with supplemental insulin) is
not associated with increased perinatal
complications as compared with insulin
Patients prefer metformin over insulin
Rowan et al, N Engl J Med 2008; 358:19

58. Feig DS, Moses RG. Diabetes Care 2011; 34: 2329 - 2330
Rowan JA et al Metformin in Gestational dibetes: The
Offspring Follow-Up (MiG TOFU): body composition at
2 years of age. Diabetes Care 2011; 34:2279-2284
? Healthier fat distribution in offspring

59. Alternative to Insulin Therapy
Glyburide:
Category C
Does not cross the placenta
Some physicians are using glyburide in
lieu of insulin given its ease of use.
Both the ACOG and ADA do not endorse
the use of glyburide in the tx of GDM
until additional RCTs support its safety
and effectiveness.

60. Oral Hypoglycemic agents
Glyburide Insulin
Achieved N BG 82% 88%
LGA infants 12% 13%
Macrosomia 7 4
C Section 23 24
Hypoglycemia 9 6
Preeclampsia 6 6
Anomalies 2 2
63
Langer NEJM
2000

63. Conclusion
Gestational diabetes is a growing health concern.
Although traditionally deemed not as dangerous for
the developing fetus as pregestational diabetes,
gestational diabetes has serious, long-term
consequences for both baby and mother.
Evidence now suggests that screening, early detection,
and management can greatly improve outcomes for
women with this condition and their babies.
Unfortunately, screening and diagnostic standards are
not uniform worldwide, which might lead to
underdiagnosis and undermanagement of the disease.

64. Conclusion
1-step diagnostic test also will be much easier
to administer and, thus, the earlier diagnosis
and treatment of GDM will lead to better
outcomes for mothers and their babies.
Although human insulin or human insulin
analogues have been the preferred treatment
for gestational diabetes for some time, oral
antihyperglycaemic agents—such as
glibenclamide and metformin—could be just as
effective for the management of the disease.

65. To Be or Not To Be , that is the question.
To Change or Not To Change .

66. Recommendation
It is time for Outpatient Clinic care for
early screening and diagnosis of GDM in
our locality :
To reduce the risk of the preinatal and
maternal morbidity .
To prevent or delay the development of
T2DM for the mother and the fetus in
their later lives .

68. LOBNA