Gestational Diabetes Mellitus Flashcards
What is the prevalence of Gestational diabetes?
7% of all pregnancies
What is the pathophysiology of GDM?
Increased insulin resistance from decreased tissue sensitivity to insulin and increased insulin clearance from the placenta
What causes decreased tissue sensitivity to insulin?
increased hormone levels : human chorionic somatomammotropin, progesterone, prolactin, cortisol
What causes increased insulin clearance by the placenta?
increased placental insullinase
What are the fetal and neonatal risks of GDM?
Macrosomia, Shoulder dystocia, Birth injuries, hyperbilirubinemia, hypoglycemia, RDS, perinatal death, childhood obesity
What are the maternal risks of GDM?
gHTN, PreE, CS delivery, increased risk of T2DM, shorter life expectancy
How much does having GDM increase your lifetime risk of developing T2DM?
increases lifetime risk by 50%
What proportion of women will have impaired glucose tolerance at 6 weeks PP?
33%
Treatment of GDM significantly decreases the risk of what outcomes?
Macrosomia, preE, CS delivery, shoulder dystocia
When should you screen women for GDM in pregnancy?
24- 28wga
What is the current recommended screening for GDM?
1 hr 50 g GTT followed by 3 hr 100g GTT if fails 1 hr
What are the indications for an early 1 hr GTT?
BMI > 25 + risk factor
What are the risk factors that should prompt early screening?
inactivity, high risk ethnicity, cHTN, PCOS, first degree relative with DM, HLD, previous GDM, previous BW > 4000g
at what gestational age should you screen women early for GDM who meet criteria? Should it be repeated?
Screen when patient presents to care, repeat at 24 - 28wga
What is the 1 hr GTT cutoff value that warrants a 3 hr GTT?
140 mg/dL
What is the 1 hr GTT cutoff value that automatically diagnoses a patient with GDM?
> 200 mg/dL
What are the cutoff values for the 3 hr GTT?
95, 180, 155, 140
How many abnormal values on the 3 hr GTT must a patient have to be diagnosed with GDM?
2 values
What are the dietary recommendations for GDM?
3 meals a day, 3 snacks. 1/3 calories from protein, 1/3 calories from fat, 1/3 calories from complex carbs
What are the Kcal recommendations per day for non-obese patient with GDM?
30 kCal/day prepregnancy weight
What are the Kcal recommendations per day for obese patient with BMI > 30 and GDM?
reduce calories by 30%, 20 kCal/day
How often should a patient with GDM check their CBGs?
4 times per day: fasting, 1hr or 2 hr post prandial following each meal
What is the fasting CBG goal?
< 95
What is 1 hr post prandial CBG goal ?
< 140
What is the 2 hr post prandial CBG goal?
< 120
What is the first line drug of choice to treat GDM?
Insulin
Does insulin cross the placenta?
No
Does metformin cross the placenta?
Yes
What drug crosses the placenta, possibly causes neonatal hypoglycemia and should not be used to treat GDM?
Glyburide
What is the recommendation for repeat US with GDM?
Growth US in the 3rd trimester
When should you start fetal testing for well controlled GDM?
34wga- 36wga
When should you start fetal testing for poorly controlled GDM or disease associated with LGA, polyhydramnios, cHTN?
32 wga
When should you deliver a patient with GDMA1?
39w0d - 40w6d
When should you deliver a patient with well controlled GDMA2?
39w0d - 39w6d
When should you deliver a patient with poorly controlled GDMA2 and other complications ?
37wga - 38w6d
When should a CS delivery be offered to a patient with GDMA?
When EFW > 4500g
How often should you check CBGs in active labor
Q 1-2 hrs
When should you start an insulin drip in labor?
if CBGs > 120
How much do insulin requirements decrease in the post partum period?
Decrease by 80%
When should you screen a patient with GDM for T2DM ?
6 - 12 weeks postpartum and then Q 3 years there after
What is the definition of Class B by Whites Classification?
age of DM onset > 20, duration of disease < 10 years
What is the definition of Class C by Whites Classification?
age of DM onset 10 - 19 years, duration of disease 10 - 19 years with benign retinopathy
What is the definition of Class D by Whites Classification?
age of onset < 10 years, duration of disease > 20 years
What is the definition of Class F by Whites Classification?
DM with Nephropathy
What is the definition of Class R by Whites Classification?
DM with proliferative retinopathy
What is the definition of Class H by Whites Classification?
DM with cardiovascular disease
How do we diagnose diabetic nephropathy during pregnancy (Class F)
> 400 mg protein excretion/24 hr prior to 20 weeks
Diabetic nephropathy affects what percent of pregnant patients with diabetes?
5- 10%
what percent of patients with diabetic nephropathy in pregnancy will develop pre-eclampsia?
50%
What is the greatest risk for developing PreE in a patient with diabetic nephropathy?
24 hr urine protein > 3g, Cr > 1.5
what percentage of patients with diabetic nephropathy will develop renal failure within 10 years?
50%
What is the leading cause of blindness in patients 24 - 64?
Diabetic proliferative retinopathy
What percentage of patient will have proliferative retinopathy if they have had DM for > 20 years?
80%
Treating blood sugars in pregnancy is associated with acute______ of retinopathy.
Progression
How do you treat proliferative retinopathy?
laser photocoagulation
What are the two major risk factors associated with pregestational diabetes?
SAB, Fetal Congenital Malformation
A hA1c of 10% in early pregnancy is associated with what percent risk of fetal congenital malformations?
20 - 25%
a hA1c of 5 - 6% in early pregnancy is associated with what percent risk of fetal congenital malformations?
None, no increased risk
Congenital malformations are increased by _____ in patients with high hA1c in early pregnancy.
2-6 fold
What is the most common congenital malformation associated with poorly controlled pregestational DM?
Cardiac defects
What other congenital abnormality is associated with poorly controlled pregestational DM?
Caudal regression and sacral agenesis
True or false: the risk of shoulder dystocia for any given BW increases if you have pre-gestational diabetes
True
Fetal growth restriction is associated with what type of DM?
Type D or greater
Neonatal risks of pregestational DM
RDS, hypoglycemia, hypocalcemia, hyperbilirubinemia, cardiac hypertrophy
What is the risk of pre-eclampsia in a patient with pregestational DM and no nephropathy?
15 - 20%
What is the risk of pre-eclampsia in a patient with pregestational DM and nephropathy?
50%
What is the risk of CS delivery in patients with pregestational diabetes?
45%
What labs should be obtained at the first prenatal visit for a patient with a history of pregestational diabetes?
TSH, EKG, 24 hr Urine protein, hA1c, opathmology apt
What is the CBG goal for 2:00 - 6:00 CBG check for a patient with pregestational diabetes
> 60 mg/dl
What fetal surveillance should be done for a patient with pregestational DM?
18 wk targeted US, Fetal echo at 24wga, serial growth US, NST/BPP starting at 32 wga, US for EFW prior to delivery
When should you deliver a patient with well controlled pregestational DM?
39w0d - 39w6d
when should you deliver a patient with poorly controlled pregestational DM, vascular compromise, or prior stillbirth?
36w0d - 38w6d
True or false: It is safe to do an operative delivery in a patient with pregestational DM?
False
How much should the the insulin dose be reduced following delivery for a pregestational diabetic?
decrease by 50%
Diabetic Ketoacidosis affects ____ percent of pregnancies with pregestational DM
5- 10 %
What are common lab abnormalities seen with DKA?
Hyperglycemia > 200, Acidosis pH < 7.3, HCO3 < 15 mEq/L, Anion Gap >12, decreased base excess < 4, positive serum acetone
What labs should you get and how often in maternal DKA?
ABG, CH7, glucose, serum ketone q 1-2 hrs
What is the typical fluid deficit in a patient with DKA?
100ml/kg of body weight
How should you replete IVF in a patient with DKA?
Give 4-6L in the first 12 hrs, 1-2L/hr for the first hr followed by 250-500 cc/hr for the next 12 hrs
What type of fluid should you use to manage DKA?
NS
What should you fluid management be when the CBG < 200?
Switch to D5 1/2 NS at 150 - 250/hr, then after 8 hrs switch to 125ml/hr
How should you replace K in DKA if < 3.3 ?
Give 20 - 30 meq until K > 3.3
How should you replace K in DKA if K 3.3 - 5.3 ?
Give 20 - 30 meq until K 4 - 5
How should you replace K in DKA if K > 5.3 ?
Do not hive KCL, recheck q 2 hrs
How should IV insulin be administered initially in DKA?
Regular insulin 0.1 - 0.2 U/kg load then 0.1 U/kg/hr
What happens if the glucose dose not fall by 50 - 70 mg/dl in the first hour?
Double the rate of insulin infusion
What should the rate of insulin infusion be when glucose is < 200 mg/dl?
0.05 - 0.1 U/kg/hr
What is the goal CBG range until resolution of DKA?
100 - 150 mg/dl
In the treatment of DKA, how much bicarb should be given if Ph is > 7.0
None
In the treatment of DKA, how much bicarb should be given if Ph is 6.9 - 7.0?
20 mmol NaHCO3 in 200 cc H20 with 10 meq KCL, repeat q 2 hrs until pH > 7.0
In the treatment of DKA, how much bicarb should be given if Ph is < 6.9 ?
40 mmol NaHCO3 in 400cc H20 with 20 meq KCL, repeat q 2 hrs until pH > 7.0
What is the fetal mortality rate associated with maternal DKA?
< 10%
What is typically seen on fetal monitoring in a patient with DKA?
Decreased variability and recurrent late deceleration
