3. What is GDM?
• Corbohydrate intolerance of variable severity
with onset or first recognition during
pregnancy
4. Pre-Gestational Diabetes
• a known diabetic becomes pregnant
• hyperglycemia presents throughout pregnancy
and not just in the 2nd half as occurs in GDM
• more prone for certain complications
5. Pathophysiology of GDM
Fetoplacental hormones
(GH, cortisol, prolactin, HPL)
Increased insulin resistance
Compensatory increase in insulin secretion
if not so Normal pregnancy
GDM
6. Insulin
resistance & Compensatory
stress due to increase in
placental insulin
hormones secretion
7. Epidemiology
• Prevalence of GDM vary worldwide because of
different criteria and screening regimen used
for diagnosing GDM in various countries
• India – 6% - 18%
8. Risk factors for GDM
• Strong family h/o DM
• Age >25 years
• Women who delivered large infants (>4Kg)
• h/o recurrent fetal loss
• Part h/o glucose intolerance / diabetes in previous pregnancies
• Obese/ over weight women (>15% of non-pregnant ideal body weight)
• h/o still-birth, unexplained neonatal death, congenital
malformations, prematurity
• h/o pre-eclampsia
• h/o polyhydramnios
• h/o traumatic delivery
• Chronic hypertension
• Recurrent severe moniliasis/UTI
9. Whom to screen?
Low risk Universal
Universal screening is good in Indian setting because of the
very high prevalence of both GDM & background T2DM
11. How to screen?
If normal glucose tolerance in 1st trimester
Repeat at 24-28 weeks
Repeat at 32-34 weeks
Repeat at later weeks (if increased
Maternal weight gain & suspected
Fetal macrosomia)
12. ADA Procedure
50 gm of GCT
(Without regard to the
time of last meal or time of the day)
If 1 hr GCT value
>140mg% <140mg%
100 gm of OGTT NORMAL
at fasting
13. • 100 gm of OGTT is positive if there is any of
the following 2 values:
• Plasma glucose at 0 hr ≥95 mg%
• Plasma glucose at 1 hr ≥180 mg%
• Plasma glucose at 2 hr ≥155 mg%
• Plasma glucose at 3 hr ≥140 mg%
14. WHO Procedure
• 75 gm of OGTT
• If 2 hr value ≥140 mg% positive for GDM
• This is parallel to impaired glucose tolerance in
non-pregnant women
• ADVANTAGES:
• Need not be fasting
• Least disturbances in pregnant women’s routine
activities
• Serves as both screening & diagnostic procedures
15. Glycemic criteria for diagnosis of different categories
of glucose intolerance by 75 gm, 2 hr OGTT
Criteria Fasting plasma 2 hr plasma
glucose glucose
Normal glucose tolerance <100 mg% <140 mg%
Impaired fasting glucose 100-125 mg% -
Impaired glucose tolerance - 140-199 mg%
Diabetes mellitus ≥126 mg% ≥200 mg%
16. Plasma glucose In pregnancy Outside
pregnancy
2 hr ≥200 mg% DM DM
2 hr 140-199 mg% GDM IGT
2 hr 120-139 mg% GGI Normal
2 hr <120 mg% Normal Normal
17. Maternal complications
Effects of diabetes on mother Effects of pregnancy on
diabetes
1st trimester – risk of recurrent abortions More insulin is necessary to achieve
metabolic control
Infection – chorioamnionitis & Progression to diabetic retinopathy
postpartum endometritis
Pre eclampsia – 10-25 % Worsening of diabetic nephropathy
Postpartum bleeding Increased risk of death for patients with
diabetic cardiomyopathy & MI
Caesarian section – due to fetal
macrosomia & CPD
18. Fetal complications
• Congenital abnormalities – due to metabolic
derangements present at the time of
conception, during blastogenesis & organogenesis
• Hyperglycmia macrosomia traumatic delivery
• Hypocalcemia
• Intermittent hypoglycemia IUGR
• Hyperviscosity syndrome
• Hyaline membrane disease
• Apnoea & bradycardia
• Unexplained fetal demise (last 4-8 weeks of gestation)
19. Effect on fetal growth
Maternal hyperglycemia
priming (16 weeks)
fetal pancreas
increased beta cell mass
Increased insulin secretion
24. Management of GDM
Diabetologist
obstetrician /physician
pediatrician dietician
25. Components of GDM management
Medical Nutrition
1 Therapy (MNT)
2 Physical activity
Pharmacological
3 therapy
26. Medical Nutrition Therapy (MNT)
• Adequate calories & nutrients
• Expected weight gain: 300-400gm/week
• Total weight gain: 10-12 kg
• Obese pregnant women: 5-6 kg
• Meal plan: to provide sufficient calories to
sustain adequate nutrition for mother & fetus
to avoid excess weight gain & PP
hyperglycemia
27. Medical Nutrition Therapy
contd…
• Calorie requirement depends on age, pre-
pregnancy weight, activity & gestational week
of pregnancy
• Increase of 300kcal/day above basal
requirement is needed in 2nd & 3rd trimester
28. Calorie counting
• Distributing calorie consumption especially
break fast
• Splitting the usual break fast into 2 equal
halves with a gap of 2 hr in between
• Undue peak in plasma glucose levels after
ingestion of the total quantity of break fast at
one time is avoided
• >90% of GDM can be managed by MNT
29. Physical Activity
Planned physical activity – those
who are capable of participating
Exercises that use upper body muscles
or those exercises which place little
mechanical stress
Brisk walking or arm exercise
while seated in a chair for at least
10 mins after each meal
31. Effects of 2 hr PG on offspring
Acute Chronic
If 2 hr PG >140mg% If 2 hr PG in 3rd trimester 120-139mg%
Increase in birth weight, neonatal Risk of having T2DM at 24 years -19%
adiposity, cord c peptide level >90th
percentile
If 2 hr PG in 3rd trimester 140-199mg%
Risk of having T2DM at 24 years -30%
32. Diagnosis of GDM
In 1st & 2nd trimester in 3rd trimester
MNT for 2 weeks MNT for 1 week
if fails if fails
Insulin therapy insulin therapy
33. Insulin therapy
Pre-mix insulin 30/70 4U–0–0
If target glycemic levels
not achieved increase 2 units every
4th day (max 10 U)
If FPG >90mg% 6U–0–4U
If 2 hr PG is >200mg% 8U–0–0
34. General concepts in insulin therapy
• Start with possible lowest effective dose
• Of the total insulin dose 2/3 in morning, 1/3 in evening
• Of the total insulin dose 1/3 is regular insulin, 2/3 is basal
insulin
• Increase gradually every 4th day according to FBS/PPBS values
• If PPBS is high, increase the dose of regular insulin in the morning
• If FBS is high, add basal insulin at night
• Insulin requirements increased by 50% from 20-24 weeks to 30-32
weeks
• GDM women don’t require >20 units/day
• Pre-GDM women during pregnancy may require higher doses
• Insulin dosages is always individualized & adjusted on follow up
35. OADs
• Tolbutamide, chlorpropamide, glipizide diffuse
across placenta freely – fetal hyperinsulinemia &
prolonged neonatal hypoglycemia
• Glyburide crosses the placenta the least
• Fetal concentration of glibenclamide reaches not
more than 1-2% of maternal levels – not
associated with excess anomalies or
hypoglycemia
• Glybenclamide – safe & equally effective as
insulin
36. Metformin
• Safe for use in GDM
• Alone or in combination with insulin – not
associated with increased perinatal
complications as compared to insulin
• Combined treatment with both insulin &
metformin – req lower dose of insulin, lesser
weight gain than those on insulin alone
37. USG fetal measurements
• Done in every trimester
• Fetal echo –must at 24 weeks to R/O cardiac
defects
• Fetal biophysical profile in late trimester
• Doppler umbilical blood flow measurement or
CTG at 36 weeks in GDM with other pregnancy
complications PE, HTN, APH, IUGR
38. Timing of delivery
• Delivery before full term avoided, unless there
is e/o macrosomia, polyhydramnios, poor
metabolic control & other obstetric
indications
• Increased obstetric interventions (induction,
caesarian section)
39. Delivery
• Maintain good glycemic control during labour
• Avoid hypoglycemia
• Lower insulin requirements are common
(often no insulin is necessary)
• Blood sugar monitoring after delivery, 24 hrs
postpartum if found to be high, follow up
• Presence of neonatologist –must.
40. Plasma glucose & Insulin/ iv fluids
during labour
Blood sugar at the onset of Insulin /iv fluids
labour
< 70 mg% 5% GNS @ 100ml/hr
90-120mg% NS @ 100ml/hr
120-140mg% 4 units HA in 1 pint NS @ 100ml/hr
140-180mg% 6 units HA in 1 pint NS @ 100ml/hr
>180mg% 8 units HA in 1 pint NS @ 100 ml/hr
41. Neonatal management
• Normal birth weight: 2.5-3.5 kg
• Monitoring for respiratory distress
• Capillary blood glucose at 1, 2, 4 hrs after
delivery & before feeding (cut off 44mg%)
• Early breast feeding
• In nursing PreGDM mothers good glycemic
control during lactation, by insulin.
42. Follow up in GDM
OGTT with 75 gm oral glucose (WHO criteria)
at 6-8 weeks postpartum
if normal
twice yearly or yearly follow up
• Considerable proportion of GDM women
continue to have glucose intolerance
44. Carry home messages……..
• Universal screening at 1st trimester, possibly at 1st ante natal visit
• Use WHO criteria with single step procedure
• Start insulin with possible lowest effective dose & stick into the insulin protocol
• FBS maintained ≤90mg%; PPBS maintained ≤120mg%
• USG & other fetal mesurements should be done at every trimester
• Proper obstetric interventions (induction, C.S.) should be needed at proper time
• Good glycemic control should be achieved during labour by using proper insulin
& IV fluids as per the protocol
• Post partum follow up is must
46. Changes in Thyroid gland
Thyrotropic asialo hCG
effect of hCG &
asialo-hCG
increase in Sr.TG conc.
Thyroid
gland enlarges
by an average of
18%
47. Increased hepatic
Increased synthesis &
estrogen decreased
metabolic
clearance of TBG
Increased total
T4 & T3 Increased
Free T4 & T3 TBG
conc. Normal
48. 5 factors that alter Thyroid function in
Pregnancy
1. Transient increase in hCG during 1st trimester
stimulates TSH-R (transient gestational
hyperthyroidism)
2. Estrogen induced increase in TBG
3. Alterations in immune system onset, exacerbation
or amelioration of underlying autoimmune thyroid
disease
4. Increase thyroid hormone metabolism by placenta
5. Increase in urinary iodide excretion decreased
thyroid hormone production in areas of marginal
iodine deficiency
49. Hypothyroidism in pregnancy
• Women with a h/o or high risk of
hypothyroidism ensure euthyroid prior to
conception & during early pregnancy
50. Whom to screen?
• if they have goiter/features of hypothyroidism
• family h/o autoimmune thyroid disease
51. When to evaluate?
• Prior to conception
• Immediately after pregnancy is confirmed
• At the beginning of 2nd & 3rd trimester
53. Treatment of Hypothyroidism
in pregnancy
• Levothyroxine is the drug of choice
• Usual dosage in non-pregnant state
1.6 mcg/kg/day (typically 100-150 mcg/day)
• Dose is increased by ≥50% during pregnancy
• Returned to previous levels after delivery
54. Diagnosis of thyrotoxicosis
during pregnancy
• Decrease in Sr.TSH levels <0.1mU/L
• In 8-14 weeks hCG causes stimulation of
thyroid gland only modest suppression of
TSH (0.1-0.4 mU/L)
• Confirmation of thyrotoxicosis Sr.TSH
<0.1mU/L; increase in free T4
55. TSH
• 0.34-4.25 mU/L
Normal
At the end of 1st • 0.1-0.4 mU/L
trimester
Diagnosis of • <0.1 mU/L
thyrotoxicosis in
pregnancy
57. Anti Thyroid Drugs
• Propyl thio uracil (PTU) usual initial dose is
100-200 mg every 6-8 hr
• Carbimazole / Methimazole usual initial
dose is 10-20 mg every 8-12 hr
• MOA: all drugs inhibit the function of TPO,
reducing oxidation & organification of iodide
59. Anti Thyroid Drugs
• No greater risk to mother & fetus
• Medical treatment is the treatment of choice
• Dosage of ATD required to control the disease
in later phases of pregnancy is decreased (
because of usual improvement in disease due
to immunosuppression decrease in TRAb in
pregnancy)
60. • PTU & methimazole crosses placenta
concentrated in fetal thyroid goiterous
hypothyroidism in fetus
• 150 mcg/day of PTU to mother decrease fetal
free T4 & increase TSH
• PTU >200mcg/day especially in 3rd trimester
fetal goiter & neonatal respiratory distress
• Sr. free T4 should be maintained in upper normal
range; no attempt made to normalize Sr.TSH conc.
61. • Daily maintenance dose of PTU ≤200mcg/day in
early pregnancy
• PTU is the drug of choice
• Pregnant women with Grave’s disease –
monitoring fetus for intrauterine thyroid
dysfunction (fetal heart rate, USG assessment of
fetal growth rate, presence of goiter)
• If dosage requirement >200mcg/day: indication
for subtotal thyroidectomy (in 2nd trimester)
62. • Beta blocker: IUGR, delayed lung
development, neonatal hypoglycemia, (can be
given in lower dose for short period)
• Post partum period is a time of major risk of
relapse
• Breast feeding is safe with lower doses of anti
thyroid drugs
63. A common clinical problem
Over-treatment of
hyperthyroidism
• Parallels influence of maternal hypothyroidism
on fetal brain development & decreased IQ
• Better to maintain in slightly hyperthyroid
state rather than slightly hypothyroid state
64. Carry home message…….
• Transient gestational hyperthyroidism is common in 1st
trimester (TSH level should be <0.1mU/L to diagnose
thyrotoxicosis)
• Look at free T4 & T3; not total T4 & T3
• PTU is the drug choice – dose in early pregnancy is <200
mcg/day; later phases <150 mcg/day
• Radio iodine treatment is contraindicated
• Subtotal thyroidectomy – indicated in 2nd trimester, if the
need of PTU >200 mcg/day
• Over treatment of hyperthyroidism is a common clinical
problem
• Keep Sr. free T4 in upper level of normal range
