CUH NHS 75th birthday logo

Infection in newborn babies – information for parents & carers

Patient information A-Z


Some newborns babies have a higher chance of becoming unwell due to infection. This is called early-onset neonatal infection and it refers to bacterial infection within the first 72 hours after birth. Delay in recognising that a baby is ill and starting treatment can lead to serious complications, including sepsis, and may be life-threatening. Sepsis is when the body’s response to infection damages its own tissues and organs. The symptoms of infection or sepsis in newborn babies can be very varied and sometimes quite difficult to identify in the early stages of infection. Therefore some newborn babies with infection or sepsis can become very unwell very suddenly. For these reasons we try to identify and closely monitor babies who are most at risk of developing infection or sepsis in order to prevent them becoming unwell.

Most early-onset neonatal infection is caused by bacteria normally found in the birth canal and Group B Streptococcus (GBS) is the commonest cause of neonatal bacterial infection. GBS is a bacteria found in the vagina and rectum of 20-40% of women. It rarely causes adult symptoms. Some women will be offered antibiotics in labour to reduce the risk of early-onset neonatal infection. To find out more information about this please see our patient information leaflet: Group B Streptococcus (GBS) – Your pregnancy and your baby

Risk factors for early-onset neonatal infection:

  • if you had a previous baby that had GBS infection
  • if GBS infection was confirmed during this pregnancy (in the vagina, rectum or urine)
  • if your baby is born early (before 37 weeks)
  • if your waters broke more than 18 hours before your baby was born (for babies born before 37 weeks)
  • if your waters broke more than 24 hours before your baby was born (for babies born after 37 weeks)
  • if you had a high temperature (above 38oC) or felt unwell during labour, and there is suspected or confirmed bacterial infection
  • if you have suspected infection of the placenta and waters surrounding your baby – this is known as chorioamnionitis

What happens if my baby has risk factors?

If there is just one of the risk factors above and your baby is well, then your midwife will recommend that your baby has at least 12 hours of observations following birth. This involves listening to and counting your baby’s heart rate and breathing rate, and checking your baby’s temperature by placing a thermometer under their arm. This is done at 1 and 2 hours after birth, then every 2 hours until your baby is at least 12 hours old, longer if there have been any abnormal observations or concerns about your baby.

If there is one of the risk factors above and your baby shows signs of being unwell, for example your baby is abnormally cold or has difficulties breathing, or if there are two or more risk factors, then your midwife will ask a paediatric doctor or advanced neonatal nurse practitioner to review your baby. With your permission, they will review your baby and discuss with you a recommended plan of care. This will include one of the following care plans depending on your baby’s individual risk factors and whether your baby appears well or unwell:

  1. Observing your baby for a minimum of 24-36 hours. Observations include listening to your baby’s heart rate and breathing rate, and checking your baby’s temperature by placing a thermometer under the arm, usually this is every 2 hours for the first 12 hours of age then every 4 hours if your baby remains well. Your baby will stay with you if they remain well as these observations can be done on the postnatal or transitional care wards (Lady Mary and Charles Wolfson wards).
  2. Taking some blood tests and starting antibiotic treatment for at least 36 hours. First some blood tests are taken to check for signs of infection (this includes a white cell count, C-reactive protein (CRP) and a blood culture). Antibiotics (usually benzylpenicillin and gentamicin) are then given through a cannula which is a small tube inserted into a vein in your baby’s hand or foot – this is called intravenous or IV medication. Babies do not absorb antibiotics well when given by mouth, therefore this is the best way to make sure they get the right dose of antibiotics. Your baby will also have regular observations during this time (see point 1 above) and will also need at least one further blood test to check the infection marker (CRP) and antibiotic level. Most babies can have their antibiotics given on the postnatal or transitional care wards (Lady Mary and Charles Wolfson wards) and you will stay with your baby during this time.
  3. Admitting your baby to the neonatal unit (NICU), for closer observation and antibiotic treatment.

How do you decide which of the care plans my baby needs?

The Rosie Hospital uses the Kaiser early onset sepsis risk calculator in conjunction with NICE (National Institute for Health and Care Excellence) guidance to assess whether your baby will require observations or antibiotics. This was developed by the Kaiser Permanente health system in California and has been shown to be effective at identifying the level of risk of infection for an individual baby. The Kaiser early onset sepsis risk calculator published by Kaiser Permanente is being used at several Neonatal Intensive Care Units nationwide and has been proven to decrease the number of babies being given antibiotics just because of a risk of infection without missing cases of serious infection. Many babies at risk of infection can simply be observed safely and only given antibiotics if their observations are not normal.

If your baby appears well and is assessed to need observations only, this does not mean they are not receiving treatment; they are receiving vital regular reviews. These observations will identify any baby who starts to show signs of infection.

There are some scenarios where the doctor or advanced neonatal nurse practitioner will always recommend taking some blood tests and starting antibiotic treatment. These include:

  • If you have had a multiple birth (twins or more) and infection is suspected or confirmed in one of the babies.
  • If you have had a previous baby with GBS sepsis or a baby who died due to infection, and you didn’t receive antibiotic treatment during labour at least 4 hours before your baby was born.
  • If your baby needs to go to NICU for help with breathing, or your baby has seizures or signs of shock.

If you had confirmed GBS in this pregnancy but your baby was born by caesarean and your waters did not break before the operation, then the risk of GBS infection is very low. Your baby will be recommended to have 12 hours of observations following birth.

If you were known to have GBS in a previous pregnancy but your baby was well and did NOT have an infection, then there is no increased risk in the current pregnancy. However, if you had GBS in a previous pregnancy then you should have been offered antibiotic treatment during your labour this time (please see Group B Streptococcus (GBS) – Your pregnancy and your baby). If this did not happen then speak to your midwife immediately as your baby will require a period of closer observation.

How do you know when to stop antibiotic treatment for my baby?


When the antibiotics are started, before giving the first dose, the doctor or advanced neonatal nurse practitioner will take a sample of blood which is sent to our laboratory to see if any bacteria grows – this is known as a blood culture. This takes 36-48 hours. If this test is clear, then antibiotic treatment can be stopped and you should be able to take your baby home as long as they are feeding well and there are no other concerns.

However, if the blood culture test shows evidence of bacterial infection or your baby becomes unwell with signs and symptoms of infection, then your baby may require a lumbar puncture test. The lumbar puncture is to look for meningitis (infection affecting the tissues around the brain) and involves collecting fluid from around the spine by inserting a small needle into the space between the vertebrae (spinal bones). This test would be discussed in full with you by a doctor or advanced neonatal nurse practitioner before being undertaken. If tests show evidence of bacterial infection in your baby, your baby will need to stay in hospital for antibiotic treatment for a longer time; usually 7 days but sometimes up to 3 weeks if meningitis is diagnosed.

Going home

Once your baby has been treated for suspected or confirmed infection they would be expected to make a full recovery, although ongoing follow-up may be needed – particularly if they have had meningitis. All babies who have had a confirmed infection will have an outpatient follow-up appointment.

If your baby only required observations for being at risk of infection, then once the doctor or advanced neonatal nurse practitioner has reviewed your baby, you and baby can go home with no further follow-up.

No special measures are required once you are home but you should seek urgent medical help (GP, NHS direct or the emergency department – consider calling 999 for an ambulance in an emergency) if you are concerned that your baby:

  • is limp and lethargic or floppy
  • is unresponsive
  • has abnormal or rapid breathing
  • is more irritable than usual
  • has blue lips
  • has a fit
  • is feeding less than usual/nappies are much les wet than usual
  • has a rash that does not fade when pressed with a glass
  • vomits green fluid
  • has blood in their stools
  • has a temperature lower than 36OC or higher than 38 OC
  • has a change in skin colour, especially if they are very pale, blue or mottled.

Future pregnancies

If your baby has had a confirmed Group B Streptococcus infection, any babies you have in the future will also be at risk of early-onset neonatal bacterial infection. You will be offered a test for this at about 36 weeks in your next pregnancy and, if required, antibiotics in labour. Please read the leaflet Group B Streptococcus (GBS) – Your pregnancy and your baby for more information.

Useful contacts and further information

References and sources of evidence

East of England Operational Delivery Network (2021) Early-onset neonatal infection – parent information.

Kaiser sepsis risk calculator:

National Institute of Clinical Excellence (NICE)

We are smoke-free

Smoking is not allowed anywhere on the hospital campus. For advice and support in quitting, contact your GP or the free NHS stop smoking helpline on 0800 169 0 169.

Other formats

Help accessing this information in other formats is available. To find out more about the services we provide, please visit our patient information help page (see link below) or telephone 01223 256998.

Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151