Neonatal Hypoglycaemia: Which Babies to Monitor, Signs and Early Feeding

In the first hours after birth, all babies experience a natural dip in blood glucose as they adapt from the constant supply through the placenta. Healthy, term babies who feed well usually cope. But some babies are at risk of prolonged or severe low blood glucose (hypoglycaemia), which can cause brain injury. Midwives and neonatal nurses are key to identifying, preventing and treating it.

Babies at risk

• Babies of mothers with diabetes (pre-existing or gestational).
• Small babies: low birth weight or small for gestational age.
• Preterm babies.
• Large babies (macrosomia).
• Babies who are cold (hypothermia), unwell, or have had perinatal asphyxia.
• Babies whose mothers took beta-blockers (e.g. labetalol) in late pregnancy.
• Babies who aren’t feeding well.

Signs (often subtle)

• Jitteriness or tremor.
• Poor feeding, floppiness, lethargy.
• High-pitched or weak cry.
• Rapid breathing, apnoea, cyanosis.
• Low temperature.
• Seizures or reduced consciousness (serious signs).

Many hypoglycaemic babies show no signs, which is why at-risk babies are monitored.

Prevention

• Skin-to-skin contact immediately after birth to keep the baby warm. See kangaroo mother care.
• Early feeding: within the first hour, then frequently (at least every 3 hours for at-risk babies).
• Support breastfeeding; colostrum is valuable. Hand-expressing colostrum antenatally may be offered to some women with diabetes, per local practice.

Monitoring

• For at-risk babies, the first blood glucose is commonly checked before the second feed (about 2–4 hours after birth), not immediately after birth, then before feeds as per protocol.
• Use a heel-prick sample and a device validated for neonatal use where possible; confirm low readings with a lab or blood gas analyser.
• Thresholds vary between guidelines (often around 2.0–2.6 mmol/L in the first 48 hours for intervention); follow your unit’s protocol.

Management

1. Feed: breastfeed or give expressed breast milk (or formula if needed).
2. Buccal dextrose gel (40%), rubbed into the inside of the cheek, alongside feeding, is effective for mild to moderate hypoglycaemia and reduces NICU admissions.
3. Recheck glucose as per protocol (often 30–60 minutes after treatment).
4. If glucose remains low, or the baby has abnormal signs, seizures or can’t feed: escalate for IV glucose (e.g. 10% dextrose) and neonatal admission.

Keep mother and baby together

Where safe, manage hypoglycaemia with mother and baby together to support breastfeeding and bonding. Explain to parents why tests are needed and what signs to report.

Related: Gestational diabetes · Breastfeeding support · Neonatal sepsis

Based on BAPM framework for identification and management of neonatal hypoglycaemia, WHO newborn care guidance and the Sugar Babies trial evidence on dextrose gel. Educational content: follow local protocols.