Diabetes Mellitus in Pregnancy

By : Ozhin Araz

What is Diabetes Mellitus?

• A metabolic condition characterized by chronic hyperglycemia as a result of defective insulin secretion, insulin action or both.

• Diabetes is the most common medical complication of pregnancy.

• Impact of elevated blood sugar:1. Pregnancy complications2. Multi-organ dysfunction3. Excess mortality

Gestational Diabetes• Defined as carbohydrate intolerance of variable severity with

onset or first recognition during pregnancy.

• The entity usually presents late in the second or during the third trimester.

• Gestational diabetes affects 3–9% of pregnancies, affecting 1% of those under the age of 20 and 13% of those over the age of 44.

Risk Factors1. Strong familial history of diabetes 2. Body mass index >30 kg/m23. Previous gestational diabetes.4. Have given birth to large infants (4 kg or more) 5. Previous polyhydromnios.6. Previous unexplained fetal losses 7. Over the age of 30 8. Ethnic group (East Asian, pacific island ancestry)

Pathophysiology

Insulin Resistance

Insulin resistance is a normal phenomenon emerging in the second trimester of pregnancy, which in cases of GDM progresses thereafter to levels seen in a non-pregnant person with type 2 diabetes.

Factors that mediate insulin resistance during pregnancy : Cortisol and progesterone are the main culprits, but human placental lactogen, prolactin and estradiol contribute, too with tumor necrosis factor alpha which is named as the strongest independent predictor of insulin sensitivity in pregnancy.

Screening

Oral glucose tolerance test (OGTT)Procedure :• CHO intake of at least 150 g/day 3 days prior then Fast for 10 to 16 hours• 100 grams or 75 grams of anhydrous dextrose powder

Drink within 5 minutes (first swallow is time zero)Terminate test should nausea and vomiting occur

• Abstain from tobacco, coffee, tea, food and alcohol during test• Sit upright and quietly during the test , Slow walking is permitted but

avoid vigorous exercise• Collect samples at 0, 1 ,2 and 3 hours

Result: Fasting blood glucose level ≥95 mg/dl (5.33 mmol/L) 1 hour blood glucose level ≥180 mg/dl (10 mmol/L) 2 hour blood glucose level ≥155 mg/dl (8.6 mmol/L) 3 hour blood glucose level ≥140 mg/dl (7.8 mmol/L)

1- Diet :• Recommendations are 30 kcal/kg for women with a BMI of 22

to 25, 24 kcal/kg for women with a BMI of 26 to 29, and 12 to 15 kcal/kg for women with a BMI above 30.

• The recommended overall dietary ratio is 33% to 40% complex carbohydrates, 35% to 40% fat, and 20% protein.

• This calorie distribution will help 75% to 80% of GDM women become normoglycemic.

Management :

• Avoid concentrated sweets and highly processed foods -contribute to unwanted weight gain:• soft drinks, ice cream, cakes and sweet.• restrict CHO to those found in vegetables and dairy products like cheese and cottage cheese

• Small frequent meals (4 hourly) instead of fewer larger meals

• Breakfast should be especially small and low in carbs because insulin resistance is highest in the morning.

• Foods rich in antioxidants have a role in reducing the incidence of fetal anomalies therefore fruits and vegetables are recommended

Management :

2- Exercise

3- Glucose Monitoring • Daily self blood-glucose monitoring had fewer macrosomic

infants and gained less weight after diagnosis.• Glycosylated hemoglobin should be determined at the end of

first trimester and three months thereafter. HBA1C level of 5-6% is desirable.

Management :

4- Medications

A- Insulin Therapy : Recommended when standard dietary management does not consistently maintain fasting plasma glucose at <95 mg/dL or the 2hour postprandial plasma glucose < 120 mg/dL .

• Total dose of 20 to 30 units OD, before breakfast, is commonly used to initiate therapy which is divided into two-thirds intermediate-acting insulin and a third short-acting insulin.

• Alternatively, weight-based split-dose insulin is administered twice daily.

• During the stabilization process of insulin dose, frequent blood sugar estimation especially at night may be necessary

Management :

B- Oral Hypoglycemic Agents (OHA): is usually avoided due to fearful effects of these drugs on the fetus but now Metformin can be used in certain circumferences due to its safety in pregnancy , especially if it was associated with Polycystic ovarian syndrome.

If blood glucose cannot be adequately controlled with a single agent, the combination of metformin and insulin may be better than insulin alone

Management :

1. On initial calculation of insulin dose, especially in unreliable patients

2. Patient with Pregnancy-induced Hypertension.3. Sever vascular diabetic disease4. At any time if there are concerns about glycaemic control,

especially if hyperemesis gravidarum develops5. In cases of diabetic complications ,e.g,diabetic ketoacidosis

Indications of hospitalization

• Insulin requirements drop to prepregnancy values immediately following delivery of the placenta.

• For women who had diabetes before pregnancy , can be restarted on their appropriate medication following the pregnancy .

• Insulin (For women with type 1 DM) is not excreted into breast milk and is considered completely safe for use during breastfeeding. The use of Metformin (for women with type 2 DM) by breastfeeding mothers is also considered safe, as very little of the drug is excreted in breast milk.

• Schedule 75-g OGTT after 6 weeks

Post-partum Follow-up

Prognosis :

• 60-70% chance of developing GDM in subsequent pregnancies.• 40-60% chance of developing type 2 diabetes in the future.• A second pregnancy within 1 year of the previous pregnancy has a

high rate of recurrence.• Children of women with GDM have an increased risk for childhood

and adult obesity and an increased risk of glucose intolerance and type 2 diabetes later in life.

Prognosis and Complications :

Complications : 1- Maternal Complication

a. During Pregnancy: 1. Preterm labour (20%) 2. UTI 3. Increased incidence of preeclampsia (25%) 4. Polyhydramnios 5. Maternal distress 6. Diabetic retinopathy and Diabetic nephropathy 7. Ketoacidosis

Prognosis and Complications :

Complications : 1- Maternal Complication

b. During Labor 1. Prolongation of labour due to big baby 2. Shoulder dystocia3. Perineal injuries 4. Postpartum hemorrhages5. Operative interferences

c. Puerperium: 6. Puerperal sepsis 7. Lactation failure

Prognosis and Complications :

Complications :

2- Fetal and Neonatal Complication

a. Fetal complications 1. Fetal macrosomia (%30-40)2. Congenital Malformations (%10) such as Neural tube defect or

VSD.3. Birth injuries (brachial plexus)4. Growth restriction (less common)5. Unexplained fetal death

Prognosis and Complications :

Complications :

2- Fetal and Neonatal Complication

a. Neonatal complications 1. Hypoglycemia2. Respiratory distress syndrome3. Hyperbilirubinemia4. Polycythemia5. Hypocalcemia6. Hypomagnesemia7. Cardiomyopathy .

Prognosis and Complications :

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