GDM_ Dr Selim

Dr Shahjada Selim Assistant Professor

Department of EndocrinologyBangabandhu Sheikh Mujib Medical University, Dhaka

Email: [email protected], [email protected]

mailto:[email protected]

Gestational diabetes mellitus (GDM):Diabetes diagnosed in the second or third

trimester of pregnancy that is not clearly

overt diabetes.

(American Diabetes Association, 2017)

*3 to 15% of all pregnancies are complicated by diabetes*0.2% to 0.5% of all pregnancies occur in women with pre-existing diagnosis of type 1 DM *similar number has pre-existing type 2 DM

*Early in pregnancy, maternal estrogen and progesterone increase and promote pancreatic ß-cell hyperplasia and increased insulin release

*As pregnancy progresses, increased levels of human placental lactogen, cortisol, prolactin, progesterone, and estrogen lead to insulin resistance in peripheral tissues.

*Table 1 describes the diabetogenic potency and time of peak effect of these hormones. The timing of these hormonal events is important in regard to scheduling testing for GDM

*GDM results when there is delayed or insufficient insulin secretion in the presence of increasing peripheral resistance

Increased lipolysis Mother uses fat for her caloric needs & serves glucose for fetal needs Changes of gluconeogenesis Fetus preferentially utilizes alanine & other amino acids deprivng the mother of major neoglucogenic source

*Test for undiagnosed T2DM at the 1st prenatal visit in those with risk factors. B*Test for GDM at 24–28 weeks of gestation in women not previously known to have diabetes. A*Screen women with GDM for persistent diabetes at 4–12 weeks postpartum, using the OGTT. E

American Diabetes Association Standards of Medical Care in Diabetes. Classification and diagnosis of diabetes. Diabetes Care 2016; 39 (Suppl. 1): S13-S22

*If GDM is not Dx. repeated at 24-28 wks or at any time a pt. has a symtoms or signs suggestive of hyperglycemia

*Women with GDM history should have lifelong screening for development of diabetes or prediabetes at least every 3 years. B*Women with GDM history found to have prediabetes should receive lifestyle interventions or metformin to prevent diabetes. A


Low risk status: Age<25 years Weight normal before pregnancy Member of an ethnic group with low prevalence of

GDM No first degree relative of DM No H/O abnormal glucose tolerance No H/O poor obstetric outcome

High risk status:

ObesityAdvanced maternal age, >25 yrsAsian origin irrespective of agePrevious H/O DM or abnormal glucose toleranceGlycosuriaH/O poor obstetric outcome``

*At 24-28 weeks gestation in women not previously dx’d with overt diabetes*75-g OGTT; Measure plasma glucose at fasting and at 1 and 2 hours.*GDM dx’d when plasma glucose exceeds:*Fasting: 92 mg/dL (5.1 mmol/L)*1 h: 180 mg/dL (10.0 mmol/L)*2 h: 153 mg/dL (8.5 mmol/L)


Step 1: * In women not previously dx’d with overt diabetes, perform 50-g GLT (nonfasting); Measure plasma glucose at 1 hour. * If 1 hour plasma glucose level is ≥140 mg/dL* (7.8 mmol/L), proceed to step 2.

*ACOG recommends 135 mg/dL in high-risk ethnic minorities with higher prevalence of GDM.


Step 2: 100-g OGTT is performed while patient is fasting. The diagnosis of GDM is made if 2 or more of the following plasma glucose levels are met or exceeded:


Carpenter/Coustan or NDDG

Fasting 95 mg/dL (5.3 mmol/L) 105 mg/dL (5.8 mmol/L)

1h 180 md/dL (10.0 mmol/L) 190 mg/dL (10.6 mmol/L)

2h 155 mg/dL (8.6 mmol/L) 165 mg/dL (9.2 mmol/L)3h 140 mg/dL (7.8 mmol/L) 145 mg/dL (8.0 mmol/L)

Maternal effect:

Associated with poor glycaemic control Increased maternal mortality Preeclamsia Birth canal trauma Long term- Metabolic syndrome Increased CVS risk

Fetal Effect: Fetal Macrosomia Still birth Birth injury Long term- obesity and DM in offspring Hypoglycemia Hyperbilirubinemia

Dietary TherapyExerciseSelf BG monitoringAdministration of Insulin if target blood glucose

level are not met by diet aloneFetal surveillanceIntrapartum carePost partum care

Nutritional counseling by a registered nutritionist upon diagnosis

The goals of Medical nutritional therapy are to:Achieve normoglycemiaPrevent ketosisProvide adequate weight gainMaintain fetal well beingPrevent hypoglycemiaTwo weeks for diet therapy

Nutritional therapy: cont.

The major components to consider when creating a nutritional plan for women with GDM are calorie allotment, carbohydrate intake and calorie distribution. Callorie allotment is based upon ideal body weight. The suggested calorie intake is approx:-

30 kcal per kg current weight per day in pregnant women who are BMI 22-27 24 kcal per kg per for BMI of 27-29 12-15 kcal per kg for BMI of > 30 40 kcal per kg for BMI < 22

Calorie intake: CHO-55%Protein-20%Fat-25%

With this calorie distribution, 70 to 80% of women with GDM will achieve euglycemiaCalorie distribution:

3 meal 3 snacks however in overweight and obese women the snacks are eliminated.

Nutritional Therapy: cont.

Improves Insulin sensitivityUpper extremity exerciseModerate physical activity with no medical or

obstetrical contraindication

SMBG (daily self monitoring of blood glucose) superior to intermittent office monitoring

Blood glucose report should be written in a glucose dairyBlood glucose measured 4 times a day- On awakening,

1-2 hrs after each mealHba1c is a helpful ancillary testShould be checked at 4 weeks interval

Recommendations for starting Insulin: (ADA guideline)FPG> 5.8mmol/l or1 hr PG> 8.6 mmol/l2hr PG > 7.2 mmol/l

Target blood glucose:Pre prandial <5.3mmol/l1 hr post prandial <7.8 mmol/l2 hr post prandial <6.7 mmol/l

Calculating dose:Total insulin- 20-30 U/day2/3rd intermediate acting (NPH)1/3rd regular Insulin

Calculated daily dose of insulin:1st trimester-0.8 unit ×kg BW2nd trimester- 1 unit ×kg BW3rd trimester- 1.3 unit×kg BW

The dose and type of insulin used is calculated according to the blood glucose level

If the FBG is high then, an intermediate- acting insulin, is given before bedtime.

If postprandial blood glucose levels are high, then regular rapid-acting insulin are added before meals.

Insulin Therapy cont.

If both preprandial and postprandial blood glucose levels are high,then initiate a four injection per day regimen.

The insulin is divided according to the following schedule: 45% as NPH insulin(30% before breakfast & 15% before dinner) and 55% as preprandial regular insulin(22% before breakfast,18% before lunch and 14% before dinner).

A four-times daily regimen improved glycemic control and prenatal outcome compared to a twice- daily regimen.

Insulin Therapy cont.

Regular Insulin is withheld during labor ; a sliding scale of soluble insulin should be started (or infusion pump as may be fit)

Maternal hyperglycemia should be avoided during labor to prevent fetal hyperinsulinemia and subsequent neonatal hypoglycemia

Maternal blood glucose should be maintained between 4- 5 mmol/L.

Peripartum MX:

Blood glucose should be measured on the day after delivery to using criteria established for nonpregnant women.

A women with GDM should be able to resume a regular diet postpartum.

Screen women with GDM for persistent DM 6-12 weeks post partum

Lifelong screening at list every 3 years

Peripartum MX: cont.

Nearly all women(90%) with GDM are normoglycemic after delivery. However they are at risk for recurrent GDM, impaired glucose tolerance and overt diabetes.

2/3rd of women with GDM will have GDM in a subsequent pregnancy.

Future Risk:

Should be consulted with health care provider

Glucose tolerance test should be done prior to conception

GDM offers an important opportunity for the development, testing and implementation of clinical strategies for diabetes prevention.

Screening all pregnant women, achieving euglycemia in them and ensuring adequate nutrition may interrupt the vicious cycle of glucose intolerance from one generation to another.

Health & Medicine

GDM_ Dr Selim