14 - Gestational Diabetes Mellitus

Human placental lactogen (hPL)/ human chorionic somatomammotropin (hCS)

Hormone responsible for increased insulin resistance and generalized carbohydrate intolerance

Between 24-28 weeks AOG

Best time to screen for GDM

50g glucose screening test, 1hr glucose > 140 mg/dL proceed to 75- or 100-g OGTT

Two-step approach to GDM diagnosis

Dietary

Initial management for GDM

Insulin

Second-line management for GDM

Metformin, glyburide

Drugs with some evidence for benefit in GDM patients, and is recognized by ACOG as reasonable second-line drugs for GDM management

• 30-35 kcal/kg/day of ideal body weight

• 40% carbs, 20% protein, 40% fat

Suggested meal plan for GDM patients

4x/day, including fasting and three 1- to 2- hr postprandial values

Blood glucose monitoring schedules for GDM patients

White classification

Classification scheme that determines likely severity of diabetes and its interaction with pregnancy

A2: between 32-34 weeks, then q weekly/biweekly until delivery

Fetal surveillance is commonly done in patients with White classification...?

39 weeks AOG

Timing of delivery in insulin-requiring GDM patients

48%

Risk of GDM in subsequent pregnancy if with current GDM

Type 1

Pregestational DM resulting frombeta-cell destruction absolute insulin deficiency

Type 2

Pregestational DM resulting from inadequate insulin secretion + increased resistance

Overt DM

Which has higher congenital anomaly risk, GDM or overt DM?

AV septal defects

Most common fetal cardiovascular defect in overt DM patients