4. Gestational diabetes (GDM) is defined as any degree
of impaired glucose tolerance of with onset or first
recognition during pregnancy .
Many are denovo pregnancy induced
Some are type 2 ( 35-40%)
10% have antibodies
5. Difficult to distinguish pregestational Type 2 DM and denovo
GDM
Fasting hyperglycemia
blood glucose greater than 200 mg/dL on OGT
acanthosis nicgrans
HbA1C > 6%
a systolic BP > 110 mm Hg
BMI > 30 kg/m2
Fetal anomalies
Clues for Type 1
Lean
DKA during pregnancy
Severe hyperglycemia requiring large doses of insulin
6. Fuel metabolism in pregnancy
Goal is uninterrupted nutrient supply to fetus
The metabolic goals of pregnancy are
1) in early pregnancy to develop anabolic stores to meet
metabolic demands in late pregnancy
2) in late pregnancy to provide fuels for fetal growth and
energy needs.
7. Glucose metabolism in pregnancy
Early pregnancy
E2/PRL stimulates b cells –Insulin sensitivity same and
peripheral glucose utilisation – 10% fall in BG levels
Late pregnancy
Fetoplacental unit extracts glucose and aminoacids, fat is
used mainly for fuel metabolism
Insulin sensitivity decreases progressively upto 50-80%
during the third trimester
variety of hormones secreted by the placenta, especially
hPL and placental growth hormone variant, cortisol,
PRL,E2 and Prog
8. Glucose metabolism in pregnancy
Fetus
Fat
Glucose Aminoacids
Insulin Hyperins
ulinemia
FASTING
accelerated
starvation and
exaggerated ketosis
(maternal
hypoglycemia,
hypoinsulinemia,
hyperlipidemia, and
hyperketonemia)
FED
hyperglycemia,
hyperinsulinemia,
hyperlipidemia,
and reduced tissue
sensitivity to
insulin
9. RISK FACTORS
History of macrosomia:birth weght>4 Kg,h/o GDM previous
pregnancy
Race
Polycystic ovarian syndrome
Essential hypertension or pregnancy-related hypertension
history of spontaneous abortions and unexplained stillbirths
strong family history of diabetes (especially in first-degree
relatives)
obesity ( [BMI] > 30)
age older than 25 years
persistent glucosuria
10. “NO KNOWN RISK FACTORS IN 50% OF GDM”
ADA recommends selective screening for GDM, but
according to indian guidelines we follow universal
screening
11. Maternal complications
Worsening retinopathy – 10% new DR, 20% mild NPDR and
55% mod-severe NPDR progresses
Worsening proteinuria. GFR decline depends on
preconception creatinine and proteinuria
Hypertension and Cardiovascular disease
Neuropathy – No worsening (gastroparesis, nausea,
orthostatic dizziness can be worsened)
Infection
14. Diagnosis of GDM
The WHO 1999 criteria.
Introduced in 1999.
Glucose load is 75g.
GDM diagnosed if the plasma glucose is 140mg /dl or
above 2 hours after the glucose load.
In 2013 ,WHO dropped in own 1999 criteria and
accepted the IADPSG criteria.
15. IADPSG guidelines
Screening for GDM.
Performed at 24 to 28 weeks of gestation.
75g two hour OGTT is used.
GDM is diagnosed if any one value exceeds the
thresholds shown below.
fasting 1hr 2hr
Plasma glucose ≥92 ≥180 ≥153
(mg/dl)
16. Whom and when to screen? Indian
Scenario - The DIPSI Guidelines
75 gm GCT with single PG at 2 hrs –
≥ 140 mg/dL is GDM
≥ 120 mg/dL is DGGT
>200mg/dl is diabetes
Universal screening
First trimester, if negative at 24 – 28 weeks and then at 32 – 34
weeks
17. Why in India,separate guidelines for
screening?
Indian females-11 fold increased risk of GDM than
Caucasians.
Prevalence is 16.55%
Universal screening detects more number of GDM.
Single blood glucose measurement after
GCT,economically feasible,more patient compliance.
19. MANAGEMENT ISSUES
Patient education
Medical Nutrition therapy
Pharmacological therapy
Glycemic monitoring: SMBG and targets
Fetal monitoring: ultrasound
Planning on delivery
20. If FPG >120,start insulin
Others:Advise MNT,3 days of SMBG,fasting,and 3 one and
half hour post prandial blood glucose.
After MNT,1-2 weeks,start insulin if majority of fasting
ie,four-seven >90
Or majority of any one of PP >120
21. Medical nutrition therapy
Goals
Achieve normoglycemia
Prevent ketosis
Provide adequate weight gain
Contribute to fetal well-being
Nutritional plan
Calorie allotment
Calorie distribution
CH2O intake
22. Calorie allotment
30 kcal per kg current weight per day in pregnant women
who are BMI 22 to 25.
24 kcal per kg current weight per day in overweight
pregnant women (BMI 26 to 29).
12 to 15 kcal per kg current weight per day for morbidly
obese pregnant women (BMI >30).
40 kcal per kg current weight per day in pregnant women
who are less than BMI 22.
23. Postprandial blood glucose concentrations can be
blunted if the diet is carbohydrate restricted. Complex
carbohydrates, such as those in starches and
vegetables, are more nutrient dense and raise
postprandial blood glucose concentrations less than
simple sugars.
Carbohydrate intake is restricted to 33-40% of calories,
with the remainder divided between protein (about 20%)
and fat (about 40%).
With this calorie distribution, 75 to 80 percent of women
with GDM will achieve normoglycemia.
24. Calorie distribution
Variable opinion
Most programs suggest three meals and three snacks;
however, in overweight and obese women the snacks are
often eliminated
Breakfast — The breakfast meal should be small
(approximately 10%of total calories) to help maintain
postprandial euglycemia. Carbohydrate intake at
breakfast is also limited since insulin resistance is
greatest in the morning.
Lunch — 30% of total calories
Dinner — 30% of total calories
Snacks — Leftover calories (approximately 30% of total
calories) are distributed, as needed, as snacks.
25. Diabetes in Pregnancy: Physical Activity
Unless contraindicated, physical activity should be
included in a pregnant woman’s daily regimen
Regular moderate-intensity physical activity (eg, walking)
can help to reduce glucose levels in patients with GDM
Other appropriate forms of exercise during pregnancy
Cardiovascular training with weight-bearing, limited to the upper
body to avoid mechanical stress on the abdominal region
26. Monitoring BG
Atleast 4 times-self monitoring
Fasting and 3 one and half hour postprandial
After achieving target level,lab monitoring till 28 weeks
once in a month
28-32 weeks once in 2 weeks
>32 once a week
Other parameters to be monitored:fundus,micro
albuminuria
27. Glycemic targets
Mean plasma glucose of 105 mg/dl
Achieved by maintaining FPG at 90 & PP at 120
Mean plasma glucose should never go below 86
28. INSULIN THERAPY
Type of insulin used-always human insulin or analogues
In India,basal insulin is usually given as NPH.
Basal may be provided with long acting or intermediate acting
or continuos infusion
Insulin for post prandial control-short acting(regular or
analogue)
NPH-intermediate acting-category B
Detemir-long acting category B
Lispro,aspar ultra short acting-category B
Glargine-long acting-category C
29. INSULIN THERAPY
NPH is usually started at 4 units and then titrated
If morning PP is more,regular insulin in morning
If predinner is high,night dose of rapid insulin
Mixed split regimen-total insulin requirement-2/3 in
morning,1/3 night,of each dose 1/3 rapid and 2/3
intermediate acting.
30. Insulin
≈ 15% need insulin
Total dose varies. ≈ 0.7 to 2 units per kilogram (present pregnant
weight)
FBG high – Night NPH ≈ 0.2 units/kg
PPBG high – bolus ≈ 1.5 units/10 gm CH2O for breakfast and ≈ 1
unit /10 gm CH2O for lunch and dinner
If both pre and postprandial BG high or if the woman's
postprandial glucose levels can only be blunted if starvation
ketosis occurs - four injection/day regimen.
Total 0.7 unit/kg up to week 18
0.8 unit/kg for weeks 18 to 26
0.9 unit/kg for weeks 26 to 36
1. unit/kg for weeks 36 to term.
In a morbidly obese woman, the initial doses of insulin may need to
be increased to 1.5 to 2. units/kg to overcome the combined insulin
resistance of pregnancy and obesity.
31. Status of OHA in pregnancy
Metformin and the sulfonylurea glyburide are the 2 most commonly
prescribed oral antihyperglycemic agents during pregnancy
Due to efficacy and safety concerns, the ADA and DIPSI does not
recommend oral antihyperglycemic agents for gestational diabetes mellitus
(GDM) or preexisting T2DM
Medication Crosses
Placenta
Classification Notes
Metformin Yes Category B Metformin and glyburide may be
insufficient to maintain normoglycemia at
all times, particularly during postprandial
period
Glyburide Minimal
transfer
Some formulations
category B, others
category C
33. Management Intrapartum
Attention to labor pattern, as cephalopelvic disproportion may
indicate fetal macrosomia
If steroids or beta agonists used,increase insulin
Skip morning insulin on day of induction.
Usually no need of insulin while labour.
Hourly blood glucose monitoring during active labor, with
insulin drip if necessary
Notify pediatrics if patient has poorly controlled blood sugars
antepartum or intrapartum
34. Management Postpartum
For patients with pregestational diabetes, halve dose of
insulin and continue to check blood glucose in immediate
postpartum period
For GDM patients who required insulin therapy (GDMA2),
check fasting and postprandial blood sugars and treat with
insulin as necessary
For GDM patients who were diet controlled (GDMA1), no
further monitoring nor therapy is necessary immediately
postpartum
35. Metformin and glyburide are secreted into breast milk and are
therefore contraindicated during lactation
Breastfeeding plus insulin therapy may lead to severe
hypoglycemia1
Greatest risk is in women with T1DM
Preventive measures are: reduce basal insulin dosage and/or
carbohydrate intake prior to breastfeeding
For baby,start early breast feeding,CBG at 1 hour and 4 values in
first 24 hours,before each feed.<44 is considered hypoglycemia.
36. Management Postpartum
For all GDM patients, perform 75 gram 2-hour OGTT
at 6 week postpartum visit to rule out pregestational
diabetes
Most common recommendation is for primary care
physician to repeat
2-hour OGTT every three years
37. Who will progress to DM?
WC and BMI – stronset predictors
Autoantibodies
DM at earlier gestational age
Gestational requirement of insulin
Higher FBG
Higher BG on OGTT
Neonatal hypoglycemia
Recurrent GDM
