Hypoglycaemia (low blood sugar) and your baby

You have been given this information because your baby is at increased risk of having low blood sugar (also called low blood glucose or hypoglycaemia).

Your baby might have low blood sugar in the first few hours or days after birth if:

  • they are small
  • they are premature (born before 37 weeks)
  • the birth parent has diabetes
  • the birth parent takes beta blockers

Extremely low blood glucose is a serious condition. If not treated, it can cause brain injury and problems with your baby's development. However, low blood glucose can be treated to avoid harm to your baby.

We recommended that they have some blood tests to check their blood glucose level. This continues until they are stable, and until they are 8 hours old or more.

It's important your baby is kept warm and fed regularly to keep their blood glucose levels normal.

Antenatal hand expressing

If you know while you are pregnant that your baby will be at risk of hypoglycaemia, you might want to consider trying to express some colostrum antenatally (before birth). This will make sure you are confident in the skill of hand expressing and might provide some colostrum for you to bring in if baby is slow to establish feeding. 

How we care for your baby

We ask that your baby wears a red hat while in hospital. This tells us that your baby needs to be kept warm and monitored closely.

Please make sure:

  • your baby wears the red hat (unless it is extremely hot in summer)
  • you display the red hat sign on your baby’s cot

The midwives will tell you when it's safe to stop. This will be once your baby’s blood glucose levels and temperature are stable.

Once your baby’s temperature has stabilised, it is no longer recommended that they wear a hat indoors due to risk of sudden infant death syndrome (SIDS).

Blood glucose testing

We do a blood test to check your baby’s blood glucose. A very small amount of blood is collected by pricking your baby's heel. It can be done while you are holding your baby in skin-to-skin contact.

You and your baby will need to stay in hospital for the blood tests.

The first blood test should be done before the second feed (2 to 4 hours after birth).

We repeat this test before every feed until the blood glucose levels are stable for 2 consecutive tests (one after the other).

Please let your midwife know when you are planning to feed your baby so that the blood test can be done at the correct time.

You will know the result of each test straight away.

Checking your baby is well

Do not hesitate to tell staff if you are worried about your baby. The following are signs to check that your baby is well.

Tell a member of staff if:

  • your baby becomes less interested in feeding
  • your baby is struggling to breathe with deep chest movements, nostrils flaring or making noises with each breath out
  • your baby is cold to the touch (hand and feet can sometimes feel a little cooler)
  • your baby does not respond to you
  • your baby feels completely floppy
  • your baby makes strong, repeated, jerky movements
  • your baby's lips and tongue do not look pink
  • your baby is breathing very fast

Is your baby feeding well?

In the first few days, your baby should feed effectively at least every 3 hours, until their blood glucose is stable. After that, they should feed at least 8 times in 24 hours.

Ask a member of staff how to tell if your baby is attached and feeding effectively at the breast, or how much formula your baby needs.

If your baby becomes less interested in feeding than before, this may be a sign they are unwell and you should raise this with a member of staff.

Is your baby warm enough?

Your baby should feel slightly warm to touch, although hands and feet can sometimes feel a little cooler.

Is your baby alert and responding to you?

When your baby is awake, they will look at you and pay attention to your voice and gestures. If you try to wake your baby they should respond to you in some way.

Is your baby’s muscle tone normal?

A sleeping baby is very relaxed but should still have some muscle tone in their body, arms and legs should respond to your touch. Your baby might be unwell if they:

  • feel completely floppy, with no muscle tone when you lift their arms and legs
  • make strong, repeated, jerky movements

It can be normal to make brief, light jerky movements. Ask a member of the team if you are not sure about your baby’s movements.

Is your baby’s colour normal?

Look at the colour of the lips and tongue. They should be pink.

Is your baby breathing easily?

Babies’ breathing can be irregular, sometimes pausing for a few seconds and then breathing very fast for a few seconds.

It is not normal for your baby to:

  • breathe very fast (more than 60 breaths per minute) for a continuous period
  • make very deep chest movements, noises with each breath out or flare their nostrils. These are signs they might be struggling to breathe

If your baby’s blood glucose is low

If the blood glucose is low, your baby should feed as soon as possible and get skin-to-skin contact.

If you are breastfeeding and your baby does not breastfeed straight away, a member of staff will check your baby to work out why. If they are happy that your baby is well, they will support you to hand express your milk and give it by oral syringe, finger or cup.

If your baby has not breastfed and you have been unable to express your milk, we can give some glucose (a type of sugar) oral gel as this can be an effective way of bringing up the blood glucose level. A top up of formula may also be advised.

If you are breastfeeding and advised to give some infant formula, this is most likely to be only for 1 or a few feeds. You should continue to offer breastfeeds and try to express milk as often as possible to ensure you milk supply is stimulated.

Urgent treatment

If the blood glucose level is very low, your baby is too sleepy or unwell to feed, or if the blood glucose is continues to be low despite feeding, the neonatal team may advise urgent treatment to raise the blood glucose level.

We might need to transfer your baby to the neonatal unit in Evelina until your baby’s blood glucose is stable.

How you can care for your baby

Skin-to-skin contact

Holding your baby on your chest helps keep your baby calm and warm. It also helps with starting to breastfeed. During skin-to-skin contact, your baby should wear a hat and be kept warm with a blanket or towel.

Keep your baby warm

Put our red hat on your baby for the first few days they are in hospital. Keep your baby in skin contact on your chest covered with a blanket. Look into your baby’s eyes to check that they are well in this position, or keep warm with blankets if left in a cot.

Feed as soon as possible after birth

Ask us to support you with feeding. We'll help you until you are confident, and make sure you know how to tell if breastfeeding is going well, or how much formula to give to your baby.

Feed as often as possible in the first few days

Offer your baby a feed whenever you notice feeding cues, such as:

  • rapid eye movements under the eyelids
  • mouth and tongue movements
  • body movements and sounds
  • sucking on a fist

Don’t wait for your baby to cry as this can be a late sign of hunger.

Feed for as long, or as much, as your baby wants.

Feed as often as your baby wants, but do not leave your baby more than 3 hours between feeds.

Express your milk (colostrum)

If you are breastfeeding and your baby struggles to feed, try to give some expressed breast milk. A member of staff will show you how to hand express your milk, or watch the hand expression videos.

If possible, it is good to have a small amount of expressed milk saved in case your need it later, so try to express a little extra breast milk in between feeds.

Useful information

Read our information about expressing your breast milk.

Unicef UK Baby Friendly Initiative produced a short film about hand expression

Resource number: 4584/VER2
Last reviewed: November 2022
Next review due: November 2025

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