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Flashcards in Diabetes Deck (15)
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What are the OGTT values used to diagnose GDM?

fasting >/= 5.1
1 hour >/= 10
2 hour >/= 8.5


What HbA1c levels indicate insulin resistance and diabetes mellitus?

IR = 39-47
DM = >/=48


What is the routine testing for diabetes in pregnancy?

Booking Hba1c
26-28 weeks OGTT

2 step polycose screening is no longer supported.


Who requires GDM screening at earliest opportunity after pregnancy confirmed? And how is this screening conducted?

2 moderate OR 1 major risk factor:

Moderate risk factors for GDM
• Ethnicity: Asian, Indian subcontinent, Aboriginal, Torres Strait Islander, Pacific Islander, Maori, Middle Eastern, non‐white African
• BMI 25 – 35 kg/m2

High risk factors for GDM
• Previous GDM
• Previously elevated blood glucose level
• Maternal age ≥40 years
• Family history DM (1st degree relative with diabetes or a sister with GDM)
• BMI > 35 kg/m2
• Previous macrosomia (baby with birth weight > 4500 g or > 90th centile)
• Polycystic ovarian syndrome
• Medications: corticosteroids, antipsychotics

HbA1c AND 75g 2h OGTT at earliest opportunity after pregnancy confirmed. Repeat OGTT at 24-28 weeks if not diagnostic in resale pregnancy.


What is the risk of PET in GDM, T1DM, T2DM and DM with nephropathy?

GDM - 10%
T1DM, T2DM - 15-20%
DM with nephropathy - up to 50%


What should occur at the initial visit for women with pre-existing DM?

Booking bloods
retinopathy screening (if not within last 3 months)
Ensure taking higher dose 5mg folic acid and iodine

TFTs and consider coeliac screening in T1DM


When should delivery be planned for T1DM/T2DM and GDM?

T1DM/T2DM = 37-38+6 (risk stillbirth increases dramatically from 39wk)
GDM = Delivery by 40+6; earlier dependant on risk factors


What are the risks and what is the counselling for a woman with diabetes and LGA baby >/= 4.5kg?

20% risk of shoulder dystocia.

Offer ElCS.

NB. NNT 443 to prevent 1 permanent brachial plexus injury.


What are the diagnostic levels for pre-existing DM?

fasting >/= 7.0
2 hour >/= 11.1

Random glucose >/= 11.1


What are the glycemic targets for women checking BSLs?

Fasting = 5.3
1 hour post meals = 7.4
2 hours post meals = 6.7

Pre- existing diabetes - aim to maintain HbA1C = 48 if possible without risk of hypoglycaemic episodes


How to initiate treatment in new diagnosis GDM

If fasting glucose < 7:
- Diet and lifestyle for up to 2 weeks
- If BSLs not controlled, commence metformin
- If metformin not successful or not tolerated, commence insulin

If fasting glucose >/= 7; macrosomia; diabetic complications (retinopathy/nephropathy)
- Commence insulin


When should BSLs be checked?

- Fasting, pre-meal, 1 hour post-meal, evening

T2DM/GDM on bolus short-acting insulin
- Fasting, pre-meal, 1 hour post-meal, evening

T2DM/GDM on diet, metformin or single dose long acting insulin:
- Fasting, 1 hour post-meal


What is the perinatal mortality rate for women with pre-existing diabetes T1DM/T2DM?

28 per 1000 births


How does diabetes affect the risk of congenital abnormality?

The risk of congenital abnormality doubles.
(Background risk of severe birth defects roughly 3.5% births)

Commonest abnormality:
- Congenital heart malformation
- Neural tube defects (incl: micro-/anencephaly)

Risk highest if HbA1c >/= 86 - women should be advised to use contraception until diabetic control improved.

Dose dependent relationship between risk of abnormality and HbA1c levels prior to 10 week pregnancy.


What are the long term complications of GDM? What follow-up is required postpartum?

30% recurrence risk in future pregnancies
50% risk of developing T2DM in later life
Increased risk of high BMI and diabetes in the fetus

Recommend HbA1c at 12 wks
- If pre-diabetic repeat after further 12 weeks
- If >/=48 requires initiation of management for diabetes

Annual HbA1c screening