Neonatal hypoglycaemia — case

Case summary

A term male infant is born at 39 weeks to a 32-year-old multipara whose pregnancy was complicated by gestational diabetes diagnosed at 26 weeks and managed with metformin, with a high third-trimester HbA1c. He is plump and plethoric with disproportionate truncal adiposity. At two hours of age he is jittery and a pre-feed glucose is 1.6 mmol/L after a breastfeed. [5] [3]

Candidate tasks

1. Take a focused history and examine the infant; formulate a one-line problem representation. [5]
2. Outline your immediate and stepwise management of the hypoglycaemia. [3]
3. Counsel the parents about the cause, the early plan and the longer-term outlook. [2]

Focused history and examination

• Antenatal: maternal gestational diabetes, metformin management, high third-trimester HbA1c indicating poor control, maternal drug exposure (no sulfonylurea or β-blocker), intrapartum glucose control, mode and indication for delivery. [5]
• Anthropometry: weight and centile, length and head circumference on a gestation- and sex-specific chart; disproportionate truncal adiposity confirming the hyperinsulinaemic phenotype. [5]
• Functional assessment: tone (jittery), colour (plethoric), temperature, respiratory effort, feeding competence and suck. [4]
• Neuroglycopenic signs: jitteriness and tremor, irritability, high-pitched cry, hypotonia, poor feeding, weak suck, and screen for apnoea, cyanosis and seizures. [4]

One-line summary: "A two-hour-old 39-week male, infant of a poorly controlled gestational diabetic mother with a hyperinsulinaemic phenotype, jittery with a pre-feed glucose of 1.6 mmol/L — IDM with symptomatic transitional hypoglycaemia." [5]

Immediate and stepwise management

• Feed early and keep warm: breast milk within the first hour, at least 2–3 hourly; dry, wrap, hat, aim normothermia. [5]
• Give buccal 40% dextrose gel 200 mg/kg massaged into the buccal mucosa with a feed, and recheck in 30 minutes. [3]
• Schedule pre-feed glucose monitoring through the first day and longer if low; treat the infant and the trend, not the number alone. [4]
• If glucose stays low or the infant is symptomatic: intravenous 10% dextrose 2 mL/kg bolus, then an escalating infusion titrated to a glucose infusion rate of 6–8 mg/kg/min. [1]
• Investigate if hypoglycaemia persists beyond 48–72 hours or needs a high glucose infusion rate: take the critical sample (insulin, free fatty acids, beta-hydroxybutyrate, lactate, ammonia, cortisol, growth hormone) and involve endocrinology. [6]
• Discharge once glucose-stable on full enteral feeds without treatment, feeding competently, thermally stable, and with confident parents who know the signs to return for. [3]

Counselling the parents

• Explain clearly that their baby is jittery because maternal diabetes meant more glucose reached the baby in pregnancy, driving extra insulin — and that the same extra insulin now drives the blood sugar down, which the team is actively treating with feeding and a sugar gel. [5]
• Set immediate expectations: the team will focus on feeding, warmth and blood sugar in the first hours, and most babies stabilise quickly with feeds, buccal dextrose gel and monitoring, often staying with the mother. [3]
• Be honest about the longer view: most infants recover fully from a transient dip, but severe or recurrent hypoglycaemia can affect development — which is exactly why the team monitors and treats proactively. [1]
• Reassure about breastfeeding and support it actively; invite questions, check understanding, and offer written information and a follow-up contact with clear safety-netting on the signs to return for. [2]