Gestational Diabetes Flashcards
What is gestational diabetes mellitus (GDM)?
Any degree of glucose intolerance with its onset during pregnancy and usually resolving shortly after delivery
What tests do NICE recommend to use for diagnosing GDM?
- Fasting plasma glucose
- Two-hour glucose tolerance test (GTT)
What level is recommended as diagnostic for GMD on fasting plasma glucose?
≥5.6 mmol/L
What level is recommended as diagnostic for GDM on GTT?
≥7.8 mmol/L
How do pregnancy hormones change energy consumption and storage?
- Decrease in fasting glucose levels
- Increase in fat consumption
- Delayed gastric emptying
- Increased appetite
What happens to insulin resistance in pregnancy?
It rises
What happens to post-prandial glucose levels as insulin resistance increases in pregnancy?
They rise
How is increased insulin resistance countered in normal pregnancy?
Levels of insulin rise
What happens to levels of insulin in GDM in relation to insulin resistance of pregnancy?
They do not compensate as well as they need to
What are the risk factors for gestational diabetes?
- Increasing age
- Asian or African america ethnic group
- High BMI before pregnancy
- Smoking
- Increase in weight between pregnancies
- Short interval between pregnancies
- Previous unexplained still birth
- Previous macrosomia
- Family history of T2DM or GDM
What are some protective factors against gestational diabetes?
- Physical activity
- Bariatric surgery
What are the most common symptoms of gestational diabetes?
Most women have no symptoms
Those who do have typical DM symptoms
How are most women with gestational diabetes detected?
Screening
What does NICE recommend as indications for screening for GDM at booking?
- BMI >30
- Previous macrosomic baby (≥4.5kg)
- Previous GDM
- First-degree relative with DM
- Family origin with high prevalence of diabetes e.g. South Asian, black Caribbean and middle eastern
After booking when should women be re-screened for gestational diabetes?
24-28 weeks
What test should be used to screen for GDM in women with risk factors?
2 hour oral GTT
Why is good glycaemic control in GDM important?
It seriously reduces perinatal morbidity
How can most women with GDM be managed?
With lifestyle modification
What lifestyle modifications can be useful in controlling GDM?
- Weight loss
- Diet
- Physical activity
When is weight loss advisable in GDM?
When BMI is > 27
Who should give dietary advice to women with GDM?
Specialist dietician
What should the food choices of a GDM diet reflect?
The nutritional demands of pregnancy
What is the recommended level of physical activity for women with GDM?
At least 30 minutes a day of physical activity sufficient enough to induce slight breathlessness
What is the first line medication for women with GDM who cannot control with lifestyle changes alone?
Metformin
When should metformin be started for GDM?
If blood glucose targets aren’t met within 1-2 weeks
When is insulin offered in GDM?
- Metformin is contraindicated
- Metformin is unacceptable to the woman
- Metformin and lifestyle changes have not achieved good control
- Fasting plasma glucose >7 mmol/L at diagnosis
- Fasting plasma glucose 6-6.9 mmol/L at diagnosis with macrosomia or hydramnios
What types of insulin are used in pregnancy?
Rapid acting insulin analogues (aspart and lispro)
What risks should women treated for GDM with insulin be warned of?
- Risk of hypoglycaemia
- Impaired awareness of hypoglycaemia especially in first trimester
What should all women treated for GDM with insulin have available?
A fast-acting form of glucose e.g. dextrose tablets
What should all women with GDM receive as part of their antenatal care?
- Blood glucose monitoring
- Target blood glucose
- HbA1c monitoring
- Fetal abnormality scan
- Monitoring of fetal growth and well-being
When should women with GDM test their blood glucose if they are lifestyle, metformin or single-dose of insulin?
Fasting and 1 hour post-meal every day
When should women on multiple daily injections of insulin for GDM check their blood glucose levels?
- Fasting
- Pre-meal
- 1 hour post-meal
- Bedtime
How should the target blood glucose levels be determined?
Through discussion with risk of hypoglycaemia taken into account
What are the usual target for fasting blood glucose in GDM?
5.3 mmol/L
What is the usual target 1 hour post-meal glucose in GDM?
7.8 mmol/L
Why is measuring HbA1c important in GDM?
To identify those who may have had pre-existing T2DM
When should HbA1c not routinely be measured in pregnancy?
In the 2nd and 3rd trimesters
When should women with GDM receive a fetal structural abnormality scan?
At 20 weeks
How often should women with GDM be offered USS fro assess fetal growth and amniotic fluid volume?
28-36 weeks
Is GDM a contra-indication to antenatal steroids for fetal lung maturation or tocolysis?
No
When should women with GDM not give birth after?
40+6 weeks
How do women with GDM often deliver at 40+6 weeks?
Either by induced labour or C-section
What should be considered when planning delivery in women with GDM and risks of maternal or fetal complications?
Elective birth before 40+6
What should happen to GDM medication after birth?
Discontinue immediately
What monitoring should women receive after birth for GDM?
Fasting plasma glucose test 6-13 weeks after birth to exclude diabetes
If post-natal fasting blood glucose is <6 mmol/L what is the guidance?
Low probability of having diabetes but should continue to follow lifestyle advice and need annual review
Why is important women who have had GDM continue to follow lifestyle advice and receive annual review if their post-natal fasting blood glucose is < 6mmol/L?
They are at higher risk of T2DM
If post-natal fasting blood glucose is 6-6.9 mmol/L what is the guidance?
They are at high risk of T2DM and offer advice, guidance and interventions to prevent this
If post-natal fasting blood glucose is ≥7 mmol/L what is the guidance?
They are likely to have T2DM and testing should be offered to confirm this
What are the potential obstetric complications of GDM?
- Macrosomia
- Large for gestational age
- Pre-eclampsia
- Delivery by c-section
- Shoulder dystocia
- Birth injuries
- Hypoglycaemia
What birth injuries is a baby at risk of if their mother has GDM?
- Bone fractures
- Nerve palsies
What are the potential long-term health complications of GDM on mother and baby?
Sustained impairment of glucose tolerance
- Subsequent obesity
- Impaired intellectual achievement
