SCENARIO

Julie rang the diabetes specialist nurse having confirmed pregnancy with a home test kit. Her period was two weeks late. Although she recalled being advised about the need for prepregnancy care, she thought her glucose control was good enough (HbA_1c concentration 7.9% at last check) and she had been taking a 400 µg tablet of folic acid daily. She had developed type 1 diabetes 16 years before (at age 8) and at her last annual review had no retinopathy or microalbuminuria. She controlled her diabetes with bedtime insulin glargine, plus insulin lispro (a rapid acting analogue) before meals.

An urgent appointment for the medical obstetric clinic was arranged, and telephone advice was given to achieve blood glucose levels of 3.5-5.5 mmol/l before meals and 4.0-6.5 mmol/l two hours after meals. HbA_1c concentration decreased from 7.7% at presentation to 6.3% within eight weeks and was maintained around this level for the rest of pregnancy. The 19-20 week anomaly scan showed a cardiac abnormality, later confirmed with fetal echocardiography as a ventricular septal defect. Blood pressure increased from 102/66 mm Hg to 124/84 mm Hg. Labour was induced at 38 weeks. Blood glucose concentration was maintained at between 5.5 mmol/l and 7.3 mmol/l through use of intravenous glucose and insulin. After a normal vaginal delivery the 4100 g baby boy had Apgar scores of 7 and 9 at 1 and 5 minutes respectively. The locum neonatal senior house officer was advised by the experienced midwives not to measure blood glucose at birth, and …