Gestational diabetes mellitus (GDM)

Carbohydrate intolerance of varying degree of severity with onset or first recognition during pregnancy.

• Incidence

1%-2% (our country); 1%-10% (other countries)

The impact of pregnancy on DM

• The first half of pregnancy

• Relative insulin sensitivity: insulin requirement↓

• Morning sickness: hypoglycemia

• The latter half of pregnancy

• Increased insulin resistance: placental hormones↑

• Intake↓intrapartum: hypoglycemia

• Postpartum: placental hormones↓→hypoglycemia

Effects on mother and fetus

• Effects on monther

• Spontaneous abortion

• Preeclampsia

• Infection: urinary infection

• Polyhydramnios

• Fetal macrosomia( dystocia

• Ketoacidosis (

Effects on mother and fetus

• Effects on fetus

• Fetal macrosomia

• Fetal growth restriction

• Premature labor

• Fetal malformation

• Effects on infant

• RDS

• Hypoglycemia

Diagnosis

• Diabetes mellitus complicating pregnancy

Already diagnosed or easy to be diagnosed

• GDM

• History

Family history of DM, urine glucose repeatedly (+), recurrent abortion or fetal death, candidal vaginitis

• Lab examination

• fasting plasma glucose(: ≥5.8mmol/L twice or more

• glucose screening test (50g glucose)

1 hr postchallenge ≥7.8mmol/L→ oral glucose tolerance test, OGTT

• OGTT (75g glucose)

Any two or more plasma glucose values exceed the following thresholds→ GDM

1 hr postchallenge: 5.6 mmol/L

2 hr postchallenge: 10.5 mmol/L

3 hr postchallenge: 9.2 mmol/L

4 hr postchallenge: 8.0 mmol/L

One value exceed the threshold→ abnormal glucose tolerance

Classification

• White’s classification of DM in pregnancy

A1: gestational diabetes not requiring insulin

A2: gestational diabetes requiring insulin

B: onset at ≥20 years of age or duration of <10 years C: onset at 10 to 19 years of age or duration of ≥20 years or any onset or duration but with background retinopathyor hypertension only F: nephropathy 肾病(>500mg proteinuria per day at <20 weeks of pregnancy)

H: arteriosclerotic heart disease, clinically evident

R: proliferative diabetic retinopathy or vitreous hemorrhage

T: history of renal transplant

Treatment

• Conception should be prevented in the patients with class D or F or R DM

• Diet management

• Meal plans: individualized

• Calories: 30 to 35 cal/kg (ideal body weight, IBW) per day. carbohydrates 40%-45%, protein 20%-30%, fat 30%

• Concentrated sweets: forbidden

• Six meals per day, 2 to 3 hr apart

• The adequacy of calories intake may be assessed by using daily fasting urinary ketone levels

• Medication (insulin)

• 2g glucose → 1 u insulin

• Early pregnancy: insulin↓

• Late pregnancy: insulin ↑50%-100%, peaking at 32 to 33 weeks

• Postpartum: insulin↓1/3-1/2

• Ketoacidosis: low-dose insulin, 0.1U/kg.h

• Maternal antepartum care: plasma glucose, renal function, blood pressure

• Fetal surveillance: development of fetus, placental function, maturity of fetus

• Termination of pregnancy

• With other obstetric problems → CS

• Keeping electrolytical balance

• Intrapartum: preventing hypoglycemia

• Postpartum: reducing the dose of insulin, preventing infection