Therapeutic target
Insulin therapy is indicated when stable blood glucose control cannot be achieved with the help of diet therapy, exercise, and lifestyle adjustments (see also “Other Therapy”). Blood glucose should be adjusted to the following values:
| Determination time | Blood glucose value (BG, glucose) |
| Fasting | 65-95 mg/dl (3.6-5.3 mmol/l) |
| 1h postprandial (after meal). | <140 mg/dl (<7.8 mmol/l) |
| 2h postprandial | < 120 mg/dl (< 6.7 mmol/l) |
Immediate insulin therapy should be discussed for fasting blood glucose levels > 110 mg/dl.
Therapy Recommendations
- Insulin therapy in terms of intensified insulin therapy (see below).
- See also below under “Further notes”
Notice. The current guideline on GDM advises metformin as an alternative to insulin. Comments on this are not included because the editorial team considers this to be a bold decision, as metformin is placental and follow-up of exposed children into adulthood is lacking.
Active ingredients (main indication)
Intensified insulin therapy (ICT) with a daily insulin dose of 0.3-0.5 I.U. human insulin/kg bw (current weight) is optimal:
- Conventional insulin therapy (CT).
- Fixed insulin doses (rigid regimen) with appropriately fixed sequence and size of meals (fixed carbohydrate portions)
- Administration of insulin mixture (usually 1/3 normal insulin, 2/3 intermediate insulin).
- 2 x daily (morning, evening) ≈ 2/3 of the total amount, 30 min before breakfast,≈ 1/3, 30 min before dinner.
- Morning: normal insulin (covering breakfast), intermediate insulin (for baseline needs + lunch).
- Evening: normal insulin (covering dinner), intermediate insulin (basic needs).
- No flexibility
- Intensified conventional insulin therapy (ICT).
- Basic bolus principle; variable injection behavior.
- Intensified insulin therapy (ICT):
- At least 3 insulin injections per day.
- Substitution as follows:
- Basal insulin requirement with long-acting basal insulin/delayed-release insulin (1 x /d).
- Prandial (meal-related) insulin requirement with short-acting “bolus insulin”
- Implementation with: Insulin syringe, insulin pens or insulin pumps.
- Flexible insulin doses depending on the situation.
- Insulin pump therapy (PT) Delivery of a continuous amount of alteinsulin s.c. as basal requirement, bolus alteinsulin at meals.
If good blood glucose control with this approach is not possible, a switch to insulin aspart or insulin lispro should be made
Notes
- The growth of the fetal abdominal circumference (abdominal circumference of the unborn) should be taken into account when deciding on insulin therapy.
- The use of the oral antidiabetic agents glibenclamide and metformin cannot be recommended because of too few evidence-based data. The biguanide metformin can be prescribed only in off-label use (use outside the indications or group of persons for which the drugs are approved by drug authorities).See Use of Metformin Before and During Pregnancy in Women with PCOS and Infertility.
- Note: Metformin in pregnancy increases child body weight: in the metformin group, 26 children (32 percent) were overweight or obese at age four compared with 14 children (18 percent) in the placebo group, according to one study.
- Additive metformin therapy (dose up to 2 x 1000 mg per day; vs. placebo) in addition to standard insulin therapy (MiTy study): there were no differences between the metformin and placebo groups in neonatal morbidity (neonatal morbidity) and mortality (neonatal mortality); neonatal effects were: lower birth weight, lower proportion of extremely obese neonates, and lower rate of neonatal obesity.
