Group B Streptococcus In Pregnancy and Delivery

Published 13th July 2022 | Dr Ujwala Parashar

Group B strep or GBS is a common bacteria found in the digestive system, vagina, rectum, or urethra. Many women who have group B strep have no symptoms or health concerns as the bacteria come and go from our bodies. However, some women who are infected with group B strep may pass the infection to their baby.

What problems can be caused by group B strep?
GBS can cause infections in different areas of the body including the lungs, blood, skin, or bones. Although health problems caused by GBS are uncommon, it can cause illnesses in the elderly or those with other medical conditions.

Are pregnant women affected by group B strep?
About 1 in 4 women have GBS. In pregnant women, this can cause an infection to occur in the urinary tract, placenta, womb, and the amniotic fluid. Although a pregnant woman may not experience any symptoms of GBS, she can pass the infection to her baby during labour and delivery.

How are babies affected by group B strep?
Whilst many babies who become infected by GBS remain healthy, there are a small number (approximately 1 in 200) that become very ill within their first few days of life developing serious infections such as pneumonia, blood poisoning or meningitis.

What are the different types of group B strep?

There are two different types of group B strep infections:

  • Early-onset infections which occur during the first week of life. Babies with early onset usually have symptoms within 24 hours of their birth.
  • Late-onset infections which develop weeks or even months after baby’s birth. 

What are the signs and symptoms of babies with group B strep?

Newborn babies and infants with GBS might have the following symptoms:

  • Fever
  • Vomiting
  • Feeding problems
  • Breathing problems
  • Irritability or fussiness
  • Inactivity
  • Limpness
  • Difficulty maintaining a healthy body temperature

A baby with GBS disease can quickly become seriously ill experiencing vomiting, fevers, and difficulty feeding. Unfortunately, the group B strep test does not prevent your baby developing late-onset group B strep. It is important to recognise these symptoms and if your child’s condition deteriorates quickly, call an ambulance or attend your nearest hospital Emergency Department.

What are the risk factors for your baby developing a group B strep infection?

It is more likely for babies to be infected with group B strep if:

  • They are premature - as their immune system is less developed
  • Your waters break or your baby is born before 37 weeks
  • You deliver more than 18 hours after your waters break
  • You have a fever while in labour
  • You have previously had a child with a severe group B strep infection
  • A pregnancy urine test detects group B strep
  • A group B strep test swab taken between 35-37 weeks pregnancy detects group B strep

What is the group B strep test?

Dr Ujwala Parashar routinely provides pregnant women in her care with a group B strep test. This is a painless procedure that involves taking a swab of the inside of the vagina at around 35 – 37 weeks of pregnancy. The test is undertaken at this stage as tests conducted earlier in pregnancy are not always accurate as to your condition at birth, as the bacteria can come and go.

How can group B strep be prevented from infecting your baby?

The results from your group B strep test and your medical history will guide Dr Parashar’s recommendations regarding any necessary steps needed to prevent your baby being infected with group B strep. If she determines your baby is at risk and you are having a vaginal delivery, she will recommend intravenous antibiotics when your water breaks or when you commence labour. If you have had antibiotics during labour, your baby is then monitored for the first few days after birth for signs of infection.

There is no need for antibiotics before a planned caesarean section as the baby will not pass through the vagina and group B strep cannot be passed through the placenta.

Should I be worried about my baby being infected with group B strep?

Dr Parashar considers all factors of your medical history that might indicate a risk of your baby being infected, as well as conducting a group B strep test swab. These steps are designed to minimise the risk of your baby becoming infected with GBS.

Dr Ujwala Parashar, Obstetrician & Gynaecologist

Sam Samant

Dr Ujwala Parashar is a highly trained female obstetrician and gynaecologist with over 15 years of professional experience and training, practicing in Sydney's North Shore and Barangaroo. If you would like more information on conception, or if you are seeking obstetric options and advice, please contact us or call 1300 811 827 to arrange a consultation with her.