In the first hours and days of life, your baby’s body is adjusting to feeding for itself for the first time. Blood glucose (blood sugar) is the body’s main fuel, especially for the brain. If blood glucose drops too low, this is called hypoglycaemia, and it can affect your baby’s wellbeing.
The good news: most babies regulate their blood glucose without any difficulty, and a few simple steps protect against problems. This page covers what blood glucose is, who is at higher risk, and what we do to keep your baby safe.
Glucose is a type of sugar, and your baby’s main source of energy. Before birth, your baby was supplied with glucose continuously through the placenta. After birth, your baby has to balance their own glucose by feeding and, between feeds, by drawing on internal stores.
If blood glucose drops too low (hypoglycaemia), it can affect your baby’s energy, alertness, and feeding. In healthy term babies, brief, mild dips are common and harmless. Persistent or significant hypoglycaemia, especially in at-risk babies, can affect brain function if not treated.
That is why we identify at-risk babies in advance, encourage frequent feeding, keep babies warm, and monitor blood glucose in the first hours of life when needed.
Most babies have no problem with blood glucose. Some babies are at higher risk and are monitored more closely in the first hours. Risk factors include:
If your baby is in any of these groups, the midwife will explain a feeding and monitoring plan when your baby is born.
The first feed should ideally happen within the first hour after birth. Frequent feeding (at least every 3 hours in the first 24 hours, more often if breastfeeding) is the single most important thing that keeps blood glucose stable.
Skin-to-skin contact straight after birth, and during early feeds, keeps your baby warm and stable. A cold baby burns through glucose faster, so warmth is part of glucose protection.
For at-risk babies, blood glucose is measured with a small heel-prick test before some feeds. If a level is low, we act promptly with extra feeds, expressed colostrum, formula top-ups, or, occasionally, an IV glucose drip until things settle.
For at-risk babies, we monitor for low blood glucose with blood glucose tests (a small drop of blood from the heel) at specific times in the first hours of life, usually before feeds.
If a glucose level is low:
We try to keep mum and baby together throughout. Treatment is rarely needed beyond the first 24 to 48 hours.
In the first 48 hours and after going home, tell your midwife, public health nurse or GP if your baby:
Call your GP or maternity unit straight away. If your baby is unresponsive or having a seizure, call 112/999.
