9) Maternal Medicine: Diabetes Flashcards
Incidence of diabetes in pregnancy
5% of pregnancies
- 87.5% GDM
- 7.5% T1DM
- 5% T2DM
Contraindications to pregnancy in diabetes
- IHD
- HbA1c > 86
- Severe gastroparesis
- Untreated proliferative retinopathy
- Nephropathy (Cr > 250)
At what BMI should you advise weight loss pre-conceptually?
27
Glucose control whilst planning pregnancy
Monthly HbA1c and aim for <48.
Fasting BM 5-7mmol/L
Pre-meal 4-7mmol/L at other times
Screening at pre-conception counselling
HbA1c
Retinal screening if not done in last 6 months
Renal screening - if Cr >120, ACR>30 or eGFR<45 then refer nephrology.
Who to screen for GDM?
BMI >30 Previous baby >4.5kg Previous GDM 1st degree relative DM Ethnic minority with high risk
What glycosuria to test for GDM?
2+ on one occasion or 1+ on two occasions.
When to test for late onset GDM?
If EFW > 4kg or AC >90th or growth velocity increase or polyhydramnios.
Diagnosis of GDM on OGTT
Fasting >5.6
2h >7.8
What percentage of people with GDM will require treatment?
10-20%
What treatment in GDM?
If initial fasting <7 then start with diet for 1-2 w and if targets not met then look at metformin.
Insulin if:
- Fasting >7
- Fasting 6-7 but macrosomia
- Not tolerating metformin
- Targets not achieved with metformin
Consider glibenclamide if:
- Not controlled with metformin and declining insulin
- cannot tolerate metformin
How often to monitor blood sugars in diabetes?
T1DM or T2DM/GDM with multiple dosing insulin regimen: Check 8 times per day.
T2DM/GDM with diet/oral/single dose insulin: Check 6 times per day.
Blood sugar targets during pregnancy
Fasting: 5.3
1h post-meal: 7.8
2h post-meal: 6.4
When to do HbA1c?
At booking for pre-existing diabetes and at diagnosis for GDM. Consider in 2nd/3rd trimester for pre-existing diabetes (to predict risk).
When to do retinal assessment?
Pre-conception (if not done in 6m prior)
Booking (if not done in 3m prior)
Repeat at 28 weeks
(Repeat at 16-20 weeks if retinopathy present at booking)
When to do renal assessment?
At booking if not in preceding 3 months.
When to deliver in diabetes?
37-38+6 weeks: T1DM/T2DM
Uncomplicated GDM by 40+6
When to monitor BM in labour?
Hourly (targets 4-7)
When to consider sliding scale in labour?
If persistently not maintained 4-7 and consider for T1DM at start of labour
WHen should neonatal blood sugar done?
2-4 hours
When should neonate be fed?
Within 30 minutes of birth and then every 2-3 hours until feeding maintains BM >2
(If BM<2 on 2 occasions consecutively then consider tube feeding or IV dextrose)
Risk of developing T2DM after GDM
50% by 5years
When to monitor BM in GDM postnatal?
Check BM before transfer to community care.
Fasting blood glucose or HbA1c 6-13 weeks:
- If <6 (<39), moderate risk T2DM - annual check
- If 6-7, high risk T2DM
- > 7 (>48), likely T2DM already.
Then annual HbA1c.
What percentage of pregnant women using insulin pump?
20% of those with pre-existing diabetes
Diagnostic criteria for DKA
Ketones >3 or ++
Blood sugar >11 or known diabetes
Bicarbonate <15 or pH<7.3
Treatment of DKA
- Normal Saline
- 10% dextrose at 125ml/h if BM<14
- Insulin 0.1unit/kg/h (once K >3.3)
- Add K+ if K+<5.5
Metabolic targets in DKA
- Decrease blood ketones by 0.5mmol/L/h
- Increased venous bicarbonate by 3mmol/L/h
- Decreased capillary glucose by 3mmol/L/h
Fetal and maternal mortality associated with DKA
20% fetal
15% maternal
How long can it take for CTG to normalise after resolution of DKA
4-8 hours
Percentage of diabetics with hypoglycemic unawareness in pregnancy
10%
Risk of DKA
3%
Increased risk of PET
3-4 x
Risk of PET if nephropathy and hypertension
30%
Risk of nephropathy
7%
Risk of retinopathy
2x
Risk of miscarriage
4%
Risk of stillbirth
3%
Risk of macrosomia
25%
Growth problems in DM?
Macrosomia or IUGR
Neonatal metabolic consequences
Neonatal hypoglycaemia, low calcium, increased bilirubin, polycythaemia
Increased risk of congenital abnormalities in DM
4-5x
Risk of CS in DM
60%
Increased risk of GDM with chronic steroid use
5-10x increased
Inheritance DM
5-6% T1DM
10-15% T2DM
