Gestational diabetes mellitus is a condition in which a pregnant mother, without pre-existing diabetes, develops high blood sugar levels during pregnancy. The two subtypes of gestational diabetes are:
- Type A1: abnormal oral glucose tolerance test (GTT), but normal blood glucose levels during fasting and two hours after meals – diet modification is enough to control glucose levels
- Type A2: abnormal GTT with abnormal glucose levels during fasting and/or after meals – additional therapy with insulin or other medications is required.
Risk factors for gestation diabetes mellitus:
- Maternal age >35 years old
- First degree family history of Diabetes Mellitus
- BMI > 25 kg/m2
- Pre-existing conditions – polycystic ovarian disease
- Ethnicity – asians are at highest risk
- Excessive gestational weight gain
Medications:
Inj. Human Mixtard 70/30 (intermediate acting insulin – Isophane 70%; short acting insulin – Actrapid 30%) (use insulin syringe only) depending on the HbA1c:
- HbA1c is less than 8 – 0.1 units/kg 30 mins before breakfast and 0.1 units/kg 30 mins before dinner
- HbA1c between 8 and 10 – 0.2 units/kg 30 mins before breakfast and 0.2 units/kg 30 mins before dinner
- HbA1c more than 10 – 0.3 units/kg 30 mins before breakfast and 0.3 units/kg 30 mins before dinner
- Increase dose by 1 unit every 3 days until fasting blood glucose and post meal blood glucose targets are achieved
- Check blood glucose – fasting, before rapid acting insulin blood glucose and at bedtime
Oral anti-diabetics such as metformin is often used however it is not universally recommended. Please use individual discretion and discuss with gynaecologist if needed.
Post-delivery plan:
- Monitor blood sugars regularly.
- Oral anti-diabetics are relatively contraindicated if mother is breast feeding.
- Please refer to guidelines on type 1 or type 2 diabetes as applicable.
Investigations:
- Glucose tolerance test (GTT)
- Ante-natal profile – as advised by local and national guidelines
General advice:
- Follow diabetic diet
- Regular aerobic exercise regime
Referral:
Consider referral to diabetologist or endocrinologist if patients fail to respond to above treatment or presents with additional complications.