PRE-CONCEPTION ADVICE FOR
TYPE 2 DIABETES
Why Bother?
 If conception HbA1c is >10% the congenital
malformation rate is 10%
 If the conception HbA1c is <7% the congenital
malformation rate is that of the population.
Abnormalities
 Cardiac malformation (4x)
 Neural tube defects (5x)
 Caudal regression (252x)
 Duodenal/anal atresia (4x)
 Renal anomalies (5X)
 Situs invertus (84x)
CEMACH factors around poor
outcomes
 Maternal social deprivation
 No contraception in preceeding year
 No folic acid in preceeding year
 Poor pre-conceptive care
 Poor glycaemic control before/during
pregnancy
 Pre-existing complications
Pre-conception care
• Aim for pre-conception HbA1c <7% (NICE
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state <6.1%)
Stop teratogenic medications (esp ACE1)
Lifestyle advice – smoking, alcohol, diet,
exercise
Start folic acid 5mg
Complications may deteriorate
Schedule of events
Who to contact immediately when pregnant
Glycaemic control pre-pregnancy
• Continue Metformin
• Stop ALL other oral anti-diabetic agents
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including injectables (Exenatide, Liraglutide)
Start insulin if necessary
Background – Isophane vs Lantus/Levemir
Short acting analogues Novorapid &
Humalog are safe
Blood glucose monitoring
Ketone testing strips
Contraception
• All methods are acceptable
• Women for whom pregnancy would be
dangerous need a method with low failure
rate
• OCP – may cause transient change in
diabetes control
• Combined OCP – hypertension may cause
acceleration of nephropathy & retinopathy
• Monitor closely or avoid if complications
already present
Metabolic changes
 Increased glucose to foetus
- pre meal hypoglycaemia
- increased starvation & ketosis
 Insulin resistance (to increase available
nutrients to foetus)
- post meal glucose peaks
 Foetal hyperinsulinaemia & macrosomia
Glycaemic targets
 Organogenesis to week 12
 Risk of severe hypo’s up to 14 weeks as lowest
period of insulin requirement (12 – 14 weeks)
 Weeks 14 – 28 most crucial time for
preventing macrosomia etc
 Third trimester – increased requirements
Glycaemic targets continued
 Fasting level 3.5 – 5.9 mmols/l (NICE)
 2 hours post meal <7.0 mmols/l
 HbA1c unreliable – high rate cell turnover
Post delivery
 Mostly delivered 38 to 39 weeks
 Hypo’s common in third trimester
 T2D – return to pre-pregnancy therapy unless
breast feeding (Metformin safe)
 If breast feeding – reduce insulin dose by
approx. 30%
 Contraceptive advice
Gestational Diabetes
 Any degree of glucose intolerance with an
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onset or first recognition in pregnancy – WHO
definition 1998
Fasting glucose >6mmol/l
2 hour glucose>7.8mmol/l (75G OGTT)
Marker of maternal risk of type 2 diabetes
Long term implications for the baby
Screening for GDM
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Previous GDM
Persistent glycosuria
Previous large babies (>4kg)
Current large baby (>95th centile)
Polyhydramnios
First degree relative with diabetes
PCOS
Previous unexplained stillbirth
BMI >35
Ethnicity (Asian, Afrocaribbean)
Screening for GDM
 When? – when risk factor identified and again
at 28 weeks
 How? – 75G OGTT
 Interpretation – positive if:
EITHER fasting >6.9mmol/l or
2hour >7.8mmol/l
Management
 Pre-meal <5.5mmol/l
 2 hour < 7.0mmol/l until 35 weeks then
<8.0mmol/l
 Use diet, then Metformin, then insulin if
necessary
Ongoing management
 6 week repeat OGTT to exclude ongoing DM
or IGT
 NICE – fasting glucose at 6 weeks and then
annually
 2 – 3% still have diabetes
 31% have pre-diabetes
Remember: Type 2 diabetes has same risks as type1
 Pre-pregnancy counselling reduces risks (RR
0.4)
 Tight glucose control improves outcomes –
refer immediately
 Keep on Metformin, all other anti diabetic
meds stop. Insulin as necessary
 GDM have high risk of future diabetes
Thank you to Dr Julia Platts at Llandough
Hospital for the use of her information from a
previous lecture.