Gestational diabetes mellitus (GDM) is glucose intolerance that begins or is first diagnosed during pregnancy. The risks associated with GDM are similar to those with pregestational diabetes. Screening and diagnosis typically involves a 75g oral glucose tolerance test. Management of GDM focuses on achieving metabolic control through diet, exercise, insulin or oral hypoglycemic agents. Fetal surveillance is important during pregnancy and delivery should be monitored closely due to risks of complications. Postpartum care involves glucose monitoring and determining if diabetes persists after delivery.

1. GESTATIONAL
DIABETES MELLITUS

2. GESTATIONAL DIABETES MELLITUS-
HISTORY
 AGE
 OBSTETRICAL INDEX---G—P---L---A
 CHIEF COMPLAINTS
 HISTORY OF PRESENT ILLNESS
 GESTATIONAL AGE AT DIAGNOSIS
 PREVIOUS OBS HISTORY
 FAMILY / PAST HISTORY
 DIET HISTORY
 EXAMINATION– BMI,PICCLE,VITAL, SYSTEMIC and OBSTETRIC EXAMINATION

3. GESTATIONAL DIABETES MELLITUS
 ‘any degree of glucose intolerance that either commences or is first
diagnosed in pregnancy’---ACOG
 This definition includes women whose glucose intolerance will return back
to normal after delivery
 Risks associated with GDM are almost the same as those with
pregestational diabetes
 Abnormal maternal glucose regulation occurs in around 3–10% of
pregnancies.

4. GESTATIONAL DIABETES MELLITUS-risk
factors
 The reasons for the rise in the prevalence of diabetes are mainly changes
in lifestyle, dietary habits, older age at first conception, polycystic ovarian
disease, obesity, adoption of modern lifestyle, changing eating habits and
reduced physical activity
 Family history of diabetes, past history of gestational diabetes and
ethnicity

5. GESTATIONAL DIABETES MELLITUS-in
pregnancy
 Pregnancy is a unique physiological condition. It is a diabetogenic
condition due to progressive increase in the insulin resistance. The
diabetogenic effects of pregnancy are
 Insulin resistance: l Production of human placental lactogen, cortisol,
estriol and progesterone which all have anti-insulin action Increased
destruction of insulin by kidney and placenta (insulinase) Increased
lipolysis: Mother utilizes fatty acids for her caloric needs sparing glucose
for the fetus
 Changes in gluconeogenesis: Alanine and other amino acids which are a
major gluconeogenic source in the mother is preferentially used by the
fetus

6. GESTATIONAL DIABETES MELLITUS
 In early pregnancy, there is an increased risk of hypoglycemia due to
increased insulin sensitivity. Also the nausea and vomiting common in the
first trimester contribute to reduced food intake which may cause
hypoglycemia.
 The opposite occurs from the mid second and third trimester when the
insulin resistance starts occurring to provide nutrition to the growing fetus.
This explains why gestational diabetes is common after 26 weeks of
pregnancy. It also explains the increased risk of ketoacidosis in pregnant
women with type 1 diabetes.

7. Complications of diabetes
 ACUTE COMPLICATIONS
 severe hyperglycaemia with ketoacidosis or hyperosmolar coma with a
precipitating factor like infection, dehydration
 hypoglycaemia.
 CHRONIC COMPLICATIONS -long standing hyperglycaemic state --
endothelial damage leading to small vessel or large vessel disease.
Microvascular angiopathy --Neuropathy ,Retinopathy ,Nephropathy
Macrovascular angiopathy-- Coronary artery
disease,cardiomyopathy,Stroke ,Peripheral vascular disease
 Diabetes poses short term as well as long-term effects on the health of
both the mother and the child.

8. Maternal and fetal risks
 Maternal Risk
 Abortion ,Preterm labour
 Polyhydramnios
 Pre-eclampsia -10%
 Prolonged labour
 Obstructed labour
 Caesarean section
 Uterine atony
 Postpartum hemorrhage
 Infection

9. Maternal and fetal risks
 Fetal risks
 Spontaneous abortion ,IUGR
 Intra-uterine death
 Stillbirth
 Congenital malformation
 Shoulder dystocia
 Birth injuries
 Neonatal hypoglycemia,CHEMICAL IMBALANCE
 Infant respiratory distress syndrome
 Long term sequelae

10. SCREENING AND DIAGNOSIS OF GDM
 American Diabetic Association (ADA) and the IADPSG recommend the
one-step diagnostic 75g 2 hour OGTT.
 Fasting blood glucose: 92mg/dl
 Post 1 hour: 180mg/dl
 Post 2 hours: 153mg/dl
 Carpenter and Coustan criteria (upper limits of normal): F 95, 1 hr 180, 2 hr
155, 3 hr 140 mg/dl
 NDDG (National Diabetes Data Group) criteria: F 105, 1 hr 190, 2 hr 165, 3
hr 145 mg/dl.

11. SCREENING AND DIAGNOSIS OF GDM
 Seshiah et al10 has debated that the ADA/IADPSG suggestions and cut-
offs have certain disadvantages:
 The HAPO study was essentially conducted in the Caucasian population
(except Bangkok, Hong kong). They hypothesize that ethnically Asians
have higher insulin resistance in pregnancy which may result in higher
blood glucose levels
 Also, most pregnant women do not come fasting for the antenatal visit.
Thus the dropout rate is very high when she is asked to come back for an
OGTT, especially in developing countries where the number of antenatal
visits are so few.
 Glycosylated Hb is not possible in low resource settings because of its
cost and lack of technically qualified staff

12. SCREENING AND DIAGNOSIS OF GDM
 Diabetes in Pregnancy Study Group India (DIPSI) recommended a ‘single
step’ diagnostic procedure for all patients (universal screening).
 pregnant woman is given 75g glucose load orally, irrespective of her
fasting status or timing of previous meal. GDM is diagnosed if the post 2
hour blood glucose value is >140 mg/dl. The rationale behind this test is
that a normal glucose-tolerant woman would maintain euglycemia despite
the glucose load. While in a GDM patient, the glycemic excursion
exaggerates further.
 This single step procedure has been approved by the Ministry of Health,
Govt. of India and also recommended by the WHO.

13. SCREENING AND DIAGNOSIS OF GDM
 Advantages of the DIPSI procedure are:
 Pregnant women need not be fasting and can be performed at the first
visit itself, and can be best repeated again in the second and third
trimester.
 Hardly affects the daily routine of the woman.
 Is both a screening as well as a diagnostic procedure

14. DIPSI guideline
 DIPSI guideline for diagnosis of GDM, according to 75 g oral glucose
tolerance test (Modified WHO criteria)
Criteria In Pregnancy Outside Pregnancy
2 hr. ≥ 200 mg/dL Diabetes Diabetes
2 hr. ≥ 140 mg/dL GDM IGT
2 hr. ≥ 120 mg/dL DGGT --

15. Protocol for investigation
 Testing for GDM is recommended twice during ANC.
 The first testing should be done during first antenatal contact as early as
possible in pregnancy. The second testing should be done during 24-28
weeks of pregnancy if the first test is negative Moreover, only one third of
GDM positive women are detected during first trimester.
 There should be at least 4 weeks gap between the two tests.
 If she presents beyond 28 weeks of pregnancy, only one test is to be done

16. Management
 Goal – achieve metabolic control
- good obstetrical and medical outcome
 Preconceptional counseling
 Diet
 Exercise
 Insulin/OHA

17. Preconceptional counseling
 60% -unplanned
 Should start 3-6 months before conception
 To allow sufficient time to evaluate maternal health status and maximize
glycaemic control
 Achieved by multidisciplinary team

18. Preconceptional councelling-
components
 Switch over to insulin
 Laboratory evaluation-(HbA1c=<1% upperlimit of normal range) , 24hr
urine-total protein and creatinine clerance,thyroid profile
 Special investigations-cardiac and ophthalmological evaluation
 Nutritional-folic acid supplementation(400µg/day)
5mg/day if past/family h/o NTD
 Contraception

19. Management of GDM- target sugar
levels
 The ADA recommends
 Fasting -95mg/dl
 1 hour post meal - 140mg/dl
 2 hour post meal -120mg/dl
 The DIPSI recommends
 Fasting -90mg/dl
 2 hour post meal -120mg/dl

20. Is based on number of calories necessary to maintain 1kg of body weight
BMI<20 -38kcal/kg/d
BMI20-26 - 30kcal/kg/d
BMI27-30 - 25 kcal/kg/d
BMI>30 - 12Kcal/kg/d

21. Medical Nutrition Therapy (MNT)
 The total calorie requirement ----45% carbohydrate
-----30% protein and
---- 25% fat (mainly unsaturated fats)

22. Management of GDM
 All Pregnant women who test positive for GDM for the first time should be
started on Medical Nutrition Therapy (MNT) and physical exercise for 2
weeks. The woman should walk/exercise for 30 mins a day. After 2 weeks
on MNT and physical exercise, 2 hrs PPBS (post meal) should be done.
 Thus, GDM is managed initially with MNT and physical exercise and if it is
not controlled with MNT (lifestyle changes), Metformin or Insulin therapy is
added to the MNT

23. Management of GDM
 If 2hr PPBS is ≥120 mg/dL, medical management (metformin or insulin
therapy) to be started as per guidelines.
 If 2hr PPBS is <120 mg/dL, repeat test as per high risk pregnancy protocol
i.e. to undertake 8 tests (4 regular tests and 4 additional). It is
recommended to conduct at least one test every month during 2nd and
3rd trimester. More follow-up tests can be done as recommended by the
treating physician.

24. GESTATINAL DIABETES MELLITUS
 Glucose level must also be done at 3am to document nocturnal
hypoglycemia which may occur due to excess bed time insulin resulting in
fasting hyperglycemia (Somogyi phenomenon).
 In case fasting hyperglycemia occurs without nocturnal hypoglycemia, it is
called Dawn phenomenon, the cause of which is unknown. This requires an
increase in the bed time long acting insulin.

25. Management of GDM
 The requirement for insulin increases with gestational age, glycaemic
control, obesity and other factors. Dose of insulin varies from 0.6–
1U/kg/day in divided doses depending on the trimester of pregnancy
 Total daily insulin requirement - 2 ⁄3 in the morning & 1 ⁄3 at night such
that
 Morning dose - 2 ⁄3 NPH +1 ⁄3 short acting; Predinner dose 1 ⁄2 NPH + 1
⁄2 short acting

26. Fetal Surveillance in Diabetes
 First Trimester--First trimester screening including maternal serum PAPP-A
and bHCG with ultrasound evaluation for detecting chromosomal
anomalies in the fetus must be offered between 11 and 14 weeks of
gestation (NICE guidelines).
 Second Trimester---anomaly usg, Fetal echocardiography
 Third Trimester-- The NICE guidelines suggest 4 weekly monitoring of fetal
growth from 28–36 weeks.

27. Termination of pregnancy
 uncomplicated cases of gestational diabetes (not pregestational) may be
allowed to wait for spontaneous labour upto 40 weeks with adequate fetal
surveillance.
 ACOG and NICE guidelines suggest that vaginal delivery is not
contraindicated for suspected macrosomia unless the estimated fetal
weight is .4.5kg.
 In the Indian population, the average baby weight is less. Balaji et al in
their study on the diagnosis of GDM in Indian women considered birth
weight of 90th centile, which is 3.45kg, as macrosomia.

28. Management During Labour
 Consent be taken explaining high risk, need for instrumental delivery or
caesarean, if required.
 Whole blood be cross matched and kept available.
 Morning dose of insulin is omitted and fasting blood glucose done. Aim is
to keep glucose level between 72 and 126 mg/dl.
 If blood glucose level is not maintained then dextroseinsulin neutralizing
drip is started.
 50 units of regular insulin in 50ml of normal saline is started. Dose is
adjusted according to glucose level:
 90mg/dl– 0.5U/hour l 90-126mg/dl– 1U/hour l 126-180mg/dl– 2U/hour l
180-240mg/dl-3U/hour l .240mg/dl– 4U/hour

29. Management During Labour
 It is important to monitor vitals and fluid intake and output, urinary
ketones and blood glucose level 1–2 hourly
 Fetal heart must be continuously monitored and partograph be charted in
active labour.
 Labour analgesia can be offered.
 Care must be taken during second stage. Instrumental delivery must be
undertaken with care.
 Both traumatic and atonic postpartum haemorrhage must be watched for.
 Baby should be evaluated by the neonatologist

30. Postpartum Management
 The need for insulin after delivery reduces
 The pregestational diabetics must be continued on insulin for a while and
then can resume their preconceptional medications.
 Once the patient resumes full diet by third day after delivery, a fasting and
post lunch glucose level can be done and subsequent therapy decided
 The 5th International Conference on GDM also recommends 75g OGTT for
women with GDM in 6–12 weeks postpartum. If it is normal, 3 yearly
assessments should be done. In case of diabetes or impaired tolerance,
both MNT and pharmacotherapy are required depending on degree of
intolerance.

31. CONTRACEPTIVE ADVICE
 Barrier methods are ideal.
 Progesterone only pills are also safe.
 Combined oral contraceptive pills may be best avoided, especially when
diabetes mellitus is of a long duration.
 Intrauterine devices may predispose to infection.
 A diabetic patient may undergo tubal sterilization with precaution.
Counselling the husband for vasectomy is also a good option.

32. THANK YOU