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Group B Streptococcus (GBS)

Group B Streptococcus (GBS) - What it is

What is Group B Streptococcus (GBS)?

GBS is a type of bacterium (bug) which can be found in the vagina and rectum. About one in five women carry this bacterium. GBS is not a sexually transmitted disease and in most cases, women carrying GBS will have no symptoms. However, GBS can occasionally cause serious infection in newborn babies. Very rarely, infection can also occur during pregnancy.

How is GBS detected?

GBS can be detected via a swab test or urine test. In KK Women’s and Children’s Hospital (KKH), all pregnant women who are planned for a vaginal delivery will be offered a screening test (a swab test) for GBS between 35 and 37 weeks of pregnancy.

How can GBS affect my baby?

Babies can be exposed to GBS during labour or around birth. The vast majority of babies (98 to 99%) suffer no ill effects. However, one to two percent of these babies may develop serious infections and may even die. Those who survive may develop long-term disabilities.

Which babies are at higher risk of developing GBS infection?

Babies with the following are at higher risk:

  • Premature babies (born before 37 weeks of pregnancy)
  • GBS infection in an older sibling
  • Fever in the mother during labour
  • Prolonged rupture of membranes especially if more than 18 hours have passed between waters breaking and the baby being born

What can be done to reduce the risk to my baby?

  • If you are tested positive for GBS during pregnancy or have had a previous baby with GBS infection, you will be offered antibiotics during labour
  • If you have had a urine infection due to GBS during pregnancy, it should be treated promptly, and antibiotics should also be given during labour even if the urine infection has cleared
  • If your waters break after 37 weeks of pregnancy and you are known to carry GBS, you will be offered induction of labour straight away. This is to reduce the time that your baby is exposed to GBS before birth.
  • If your labour starts before 37 weeks of pregnancy, you will be recommended to have antibiotics through a drip if you have not had a GBS swab test done
  • If you develop any signs of infection in labour, such as a fever, you will be offered antibiotics through a drip that will treat a wide range of infections including GBS

If I am planning for a caesarean delivery, do I need antibiotics?

If you are planning for a caesarean delivery, you do not need antibiotics to prevent GBS infection in your baby unless labour has started or your water bag has broken. However, you will be offered antibiotics at the time of the operation to reduce the risk of other infection associated with the surgery.

What will my treatment during labour involve?

If you need antibiotics to prevent GBS infection in your baby, these should be started as soon as possible after your labour begins, or after your water bag has broken. You will be given antibiotics through a drip and continued every 4-hourly until your baby is born. Penicillin is the antibiotic of choice. For women allergic to penicillin, a suitable alternative will be given.

How will my baby be monitored after birth?

Most babies who develop GBS infection become unwell in the first week of life (early-onset of GBS infection). Late-onset GBS infection, although less common, can occur in babies up to three months old. Having antibiotics during labour reduces the risk of early-onset GBS infection, but it does not prevent late-onset GBS infection.

Following delivery in the hospital, your baby will be monitored closely for signs and symptoms of early-onset GBS infection. Most babies who are infected with GBS show symptoms within 12 to 24 hours of birth.

Parents are advised to seek medical attention immediately if any of the symptoms below are noted at home:

  • Breathlessness / baby turning blue
  • Vomiting repeatedly
  • Fever or low body temperature (normal temperature ranges from 36.5oC to 37.5oC)
  • Poor feeding / refusal to drink milk / inability to complete feedings
  • Seizures or convulsions (fits) / stiffening of the whole body / jerking movements of the arms or legs
  • Altered behaviour such as lethargy / excessive sleepiness / drowsiness or irritability / excessive crying

What tests can be done to confirm an infection in the baby?

If your baby is suspected to have an infection, tests will be done to see whether GBS is the cause. This may involve taking a sample of your baby’s blood, fluid from around the baby’s spinal cord (lumbar puncture) and/or a chest X-ray.

How is the infected baby treated?

Babies with signs suggestive of GBS infection will be treated with antibiotics through a drip as soon as the suspicion arises. This is important as the infection can spread rapidly and the baby’s condition may deteriorate.

Babies who develop GBS infection will need intravenous antibiotics for at least 10 to 14 days. This may extend to 21 days if there is meningitis (infection involving the brain and spinal cord).

Can the GBS carrier breastfeed her baby?

Yes. GBS carriers can continue with breastfeeding. Breastfeeding has not been shown to increase the risk of GBS infection, and it offers many benefits to both you and your baby.

The information above is also available for download in pdf format.

Group B Streptococcus (GBS) - Symptoms

Group B Streptococcus (GBS) - How to prevent?

Group B Streptococcus (GBS) - Causes and Risk Factors

Group B Streptococcus (GBS) - Diagnosis

Group B Streptococcus (GBS) - Treatments

Group B Streptococcus (GBS) - Preparing for surgery

Group B Streptococcus (GBS) - Post-surgery care

Group B Streptococcus (GBS) - Other Information

The information provided is not intended as medical advice. Terms of use. Information provided by SingHealth