Poorly Controlled Diabetes in Pregnancy

Poorly controlled diabetes in pregnancy is preexisting or gestational diabetes with HbA1c above 7.0 percent or glucose repeatedly above target despite treatment. It results from missed doses, wrong doses, infection, steroids, poor diet or advancing insulin resistance. It matters because it carries the highest risk of congenital anomaly, stillbirth, macrosomia, ketoacidosis and preeclampsia.

• A very high HbA1c at booking carries a high risk of congenital anomaly.
• Rapid fall in HbA1c can worsen retinopathy.
• Treatment is intensification of insulin with monitoring.

Women report polyuria, thirst, fatigue, recurrent infections or no symptoms, with glucose readings above target. Examine blood pressure, fundal height, injection sites and look for infection.

• Large fundal height.
• Candidiasis, urinary infection, skin sepsis.
• Differential diagnosis: infection, steroid effect, missed insulin, incorrect injection technique, type 1 or type 2 diabetes, gestational diabetes, hyperthyroidism.
• Complications: ketoacidosis, hyperosmolar state, congenital anomaly, macrosomia, polyhydramnios, stillbirth, preeclampsia, retinopathy and nephropathy progression, neonatal hypoglycaemia.

The approach is to measure glucose control and look for causes and complications.

• Glucose profile: fasting, 1 hour after each meal and bedtime; targets fasting 3.5 to 5.3, 1 hour below 7.8, 2 hours below 6.4 mmol/L.
• HbA1c; urine ketones or blood ketones above 1.5 mmol/L; urea and electrolytes; full blood count; urine culture.
• Review injection technique, injection sites for lipohypertrophy, insulin storage and adherence.
• Retinal examination before intensifying; ultrasound for anomaly, growth and liquor volume.

The principle is stepwise insulin intensification with correction of causes and safety against hypoglycaemia.

• Supportive: admit if glucose is above 15 mmol/L, ketones are present or home care is unsafe; dietitian review; teach injection technique, site rotation and carbohydrate counting; remove precipitating infection.
• Pharmacological: increase isophane insulin or soluble insulin by 2 units or 10 percent every 2 to 3 days until the profile is on target; use isophane insulin 0.2 units/kg at bedtime and soluble insulin 0.1 units/kg before each meal as the starting basal bolus plan if not on insulin; total daily doses of 0.7 to 1.0 units/kg are common and doses of 1.5 units/kg occur in insulin resistance; add metformin 500 mg oral with meals increased to 1 g 12-hourly (maximum 2.5 g daily) for insulin resistance; treat infection with amoxicillin 500 mg oral 8-hourly for 7 days for urinary infection guided by culture; folic acid 5 mg oral daily to 12 weeks; aspirin 150 mg oral at night from 12 weeks to 36 weeks.
• Procedures: none.
• Special groups: retinopathy needs retinal screening before intensifying and a fall in HbA1c of no more than 2 percentage points in 3 months; neonates feed within 30 minutes, glucose at 2 to 4 hours, treat glucose below 2.6 mmol/L with dextrose 10 percent 2 mL/kg IV over 10 minutes.
• Red flags: ketones, vomiting, glucose above 15 mmol/L, glucose below 3.5 mmol/L, reduced fetal movements, fever above 38 degrees Celsius.
• Follow-up: review weekly until on target, then every 2 weeks; HbA1c every 4 weeks; growth scans every 4 weeks from 28 weeks; delivery by 38 weeks and 6 days.