Gestational diabetes (GDM) is glucose intolerance that begins or is first recognized during pregnancy. It can be caused by either pre-existing type 2 diabetes or a new onset of diabetes during pregnancy. The document discusses screening, diagnosis and management of both pre-existing diabetes and GDM during pregnancy. It aims to provide optimal glucose control to support fetal growth while avoiding risks of hyper- and hypoglycemia. Treatment involves medical nutrition therapy, glucose monitoring and may require insulin therapy in some cases. Close monitoring is needed throughout pregnancy and postpartum to support maternal and fetal health.

1. DIABETES IN
PREGNANCY

2. Pre-existing DM
Gestational diabetes

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

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

12.  Fetal:
 Congenital abnormalities
 Increased neonatal and perinatal mortality
 Macrosomia
 Late stillbirth
 Neonatal hypoglycemia
 Polycythemia
 jaundice

13. SCREENING AND DIAGNOSIS

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.

18. MANAGEMENT

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

32. Fetal monitoring
 USG:18-20 weeks,anomaly scan
 Fetal ECHO:20-24 weeks
 From 26 weeks,every 2-3 weeks-liquor volume
 Abdominal circumference monitoring>70 indication of
insulin
 Chromosomal abnormalities,NTD

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

38. Thank You