GDM Flashcards
definition of GDM
Any degree of glucose intolerance with onset or first recognition during pregnancy.
If diagnosed during pregnancy, it is gestational diabetes
how common is GDM
i. Most common medical complication and metabolic disorder of pregnancy
Who manages GDM
- OBs don’t manage these patients. These patients are managed by the endocrinologist
what do we normally see in first trimester with regards to hormones
Early in pregnancy maternal estrogens and progesterone increase and promote beta cell hyperplasia and increased insulin release.
Increase in peripheral glucose utilization and glycogen storage with reduction in hepatic glucose production results in lower fasting glucose levels.
Normally glucose levels drop
pts that already have DM need to be told about first trimester lows
who is at greater risk for GDM
iii. This is highest in ethnic groups that have higher incidence of Type 2 diabetes (Hispanic Americans, African Americans, Native Americans and Pacific Islanders).
what do we see in pregnancy with regards to placental streoids
Placental steroids and peptide hormones (ie. human chorionic sommatomammotropin, cortisol, prolactin, progesterone and estrogen) rise linearly throughout second and third trimesters.
increased tissue insulin resistance in addition to this
steroids dramatically increase demand for insulin and the sensitivity is down
this becomes a problem only if the body can’t produce enough insulin
what are the effects of insulin sensitivity and increase glucose demands on the fetus
insulin does not cross the placenta but glucose does
baby gets a bunch of extra glucose and makes insulin
stores extra glucose
baby has normal blood sugar
this puts babies at risk for low blood sugar when the cord gets cut
Ideal time to start screening for gestational diabetes
This becomes apparent between 24th-28th week. = TEST QUESTION
in mothers without GDM
The pancreas releases 1 ½ - 2 ½ times more insulin to respond to the increase in insulin resistance.
Patients with normal pancreatic function are able to meet these demands.
FBG in pts without GDM and pre-existing DM pts goal
In healthy pregnancies, mean FBG levels decline to an average of 74mg/dl with peak postprandial values (1 hour after meal) rarely exceeding 120mg/dl.
Preexisting diabetes goal is around 90
Meticulous glucose control during pregnancy has been shown to reduce the risk of macrosomia.
RF for GDM
- Advanced maternal age
- Morbid obesity
- History of GDM** – screen first
- Glycosuria
- Strong family history of DM
Approaches to testing for GDM
One-step approach: use in high risk population
Two-step approach for women at average risk at 24-28wks: (standard approach)
when would you use the ones step method for testing for GDM
Perform a diagnostic 3hr oral glucose tolerance test (OGTT) without prior plasma or serum glucose screening. Cost effective in high-risk patients or populations. (Patient needs to be on an unrestricted diet for three days)
what’s the first step for two step approach
- Screen by measuring the plasma glucose concentration 1 hr after a 50g oral glucose load.
a. Pt’s go in and they have 50g glucose load and their glucose is tested 1 hour later. If above 140 then they schedule a 3 hour) GTT. If you use 140 as the cut off, you are able to identify 80% of pt’s with GDM
when would you do a 3 hour OGTT
- If >140mg/dl then schedule a 3 hour OGTT – oral glucose tolerance test (this identifies 80% of patients with GDM)
immediate risk of GDM
- Increased incidence of cesarean section (30%)
- Preeclampsia (20-30%)
- Polyhydraminos (20%) – increased amniotic fluid
The 100g, 3 hour OGTT
Must be done after 3 days of an unrestricted carbohydrate diet and while the patient is fasting. Venous plasma glucose is measured at 1, 2 and 3 hours after a 100g-glucose load. A positive test requires that 2 values be met or exceeded.
what should you do with a abnormal value on the 3hr OGTT
One abnormal value should be followed with a repeat test one month later.
Criteria of positive 100gm OGTT
- Fasting glucose: 95mg/dl
- 1 hour glucose: 180mg/dl
- 2 hour glucose: 155mg/dl
- 3 hour glucose: 140mg/dl
long term risks of GDM
- Recurrent GDM and high risk for developing diabetes (8%/yr)
Shoulder dystocia due to macrosomia resulting in:
- Brachial plexus injury
- Clavicular fracture
- Fetal distress
- Low APGAR scores
extreme concern for babies b/c with extremely poor glucose control
- With extremely poor glucose control increase risk of fetal mortality due to fetal acidemia and hypoxia
foundation for the treatment of GDM.
BG goals of ____-and post prandial around ____
Dietary therapy is the foundation for the treatment of GDM.
-diet alone will maintain fasting and postprandial blood glucose values within target range.
Measure their blood sugar, FBG goals of < than 95 and post prandial around 130
Glucose monitoring should be done at least
Glucose monitoring should be done at least weekly with a fasting glucose and a 1 hour post prandial
Recommendations for initiating insulin therapy are:
- FBG >105mg/dl
- 1 hour PPG >140mg/dl
- Macrosomia maybe further reduced if insulin is initiated when FBG >95mg/dl.
oral DM medications
No oral diabetes medications are currently approved for use in pregnancy.
iii. Glyburide is not FDA approved for use in pregnancy but growing number of diabetes centers are using this.
does not cross the placenta
what are the fasting targets
preprandial values and 1 hr PPG
- fasting 60-90mg/dl
- Preprandial values 60-105mg/dl
- 1 hr PPG < 130mg/dl
insulin tx
Start with bed time levemir (detemir) 6 units and then titrate up if needed
- Start basal insulin first
- Rapid acting insulin is started PRN. If your after meal goes up more than 130, then just take 1 unit. If they go up to 160s, then take 2 units. If they have to do it for more than 1 time for the same meal, then take 1 unit prior to the meal
which insulins are category B
NPH, Regular, aspart, Lispro and detemir are category B
adjunctive therapy for GDM
iExercise is an adjuvant therapy in GDM. Fetal safety has been established if the
maternal heart rate is maintained <140 beats/minute at durations <1 hour and the mother stays hydrated and does not get over heated.
Growth ultrasound for fetal sized should be done once at
36-37wks gestation.
if delivery is contemplated prior to 39wks gestation.
ii. Amniocentesis for fetal lung profile if delivery is contemplated prior to 39wks gestation.
if blood sugar not well controlled, then lung development seems to be delayed
The goal of management of third trimester pregnancies in women with diabetes are to
The goal of management of third trimester pregnancies in women with diabetes are to prevent still birth and asphyxia.
Fetal Movement counting
-how frequent
and what is a reassuring result
Every night at 28 wks in <60 min
10 movements
Non stress test
how frequent
and what is a reassuring result
Twice weekly
2 heart rate accels in 20 minutes Begin at 28-30 wks w/ insulin at 36 wks
contraction stress test
Weekly
No HR decels in reponse to 3 contractions in 10 min
when would you take a pt off metformin
do not recommend to start taking but if already taking it
between 12th-17th week
Ultrasound Biophysical Profile*****
Weekly Score of 8 in 30 min 3 movements = 2
1 flexion = 2
30 secs of brthing = 2
2cm amniotic fluid = 2
