Gestational Diabetes

Universal screening start at 24-248 weeks.

Consider screening earlier in all women with BMI >25 and one or more risk factors:

• Physical inactivity
• 1st degree relative with DM
• High-risk ethnicity (AA, Latino, NA, Asian, Pacific Islander)
• Previous GDM or previous more than equal to 4000g birth
• Hypertension
• PCOS
• Prepregnancy BMI >40

Screening test:

1hr OGTT (50g): serum >130-140 , Positive screening test -->3hr OGTT (100g)

3hr OGTT (100g): Fasting plus 1hr, 2hr, 3hr. 2 or more abnormal values = GDM

Management

• Nutrition advise, diet/exercise and 4x/day blood glucose testing (fasting + 2hr postprandial). Goals for fasting 60-90 ; 2hr post prandial : <120
• If inadequate control -->  insulin (NPH q12h with preprandial short acting insulin 3-4 x daily) 0.7-2u/kg current patient weight . Oral agents used much less these days (glyburide and metformin)
• Insulin management: with active labor or gluc <70mg/dL start D5NS IVF, check fingerstick glucose qhourly. Usually pregestational DM --> IV insulin drip and titrate
• NST once or twice weekly starting at 32 weeks for controlled on medication without severe feature
• NST twice weekly starting at 32 weeks for poorly controlled
• Delivery 39-40w unless poorly controlled
• Consider C-sec for EFW >4500g 
• GDM resolves with delivery so do post partum 75g glucose (2h OGTT) at 6 weeks post partum to identify non-gestational DM for all GDM patients

Pocket Obstetrics and gynecology by K Joeph Hurt 2nd edition