About Group B Strep
Group B Strep or Streptococcus (GBS) is a normal bacterium which can be found in 20- 30% of adults in the UK, usually without any symptoms or side-effects. It’s most commonly found in our normal ‘gut flora’ and is also often found in the vagina of adult women.
GBS can occasionally cause infection, most commonly in newborn babies but also sometimes in women during pregnancy or after birth.
GBS is a recognised cause of preterm delivery, maternal infections, stillbirths and late miscarriages. Preterm babies are known to be at particular risk of GBS infection as their immune systems are not as well developed as those of full-term babies.
Overall, without preventative medicine, GBS infections affect an estimated 1 in every 1,000 babies born in the UK.
Facts and Figures about GBS
The facts and figures for GBS are stark. In the UK, on average:
- Every day a baby gets GBS
- Every week a baby dies from GBS
- Every 2 weeks a baby survives GBS to be permanently damaged (long-term mental and/or physical problems, mild to severe learning disabilities, loss of sight, loss of hearing and lung damage)
In newborn babies, there are two types of GBS disease: early and late-onset. Roughly 75% of GBS disease is early-onset, occurring in the first 6 days of life and usually apparent at birth. It’s normally characterised by the rapid development of breathing problems, associated with blood poisoning. Late-onset disease (which usually presents as GBS meningitis) occurs after the baby is 6 days old and normally by age 1 month (and rarely up to age 3 months). After age 3 months, GBS infection in babies is extremely rare.
UK guidelines from NICE and from the Royal College of Obstetricians & Gynaecologists recommend that you should be offered intravenous antibiotics as soon as possible once labour starts, and then at regular intervals until the baby is born.
This has been shown to be highly effective at preventing GBS infection in newborn babies in the following cases:
- If you have a positive rectal or vaginal swab for GBS in the current pregnancy
- If you have had a previous baby who developed GBS infection
- If you have a urinary tract infection caused by GBS during pregnancy (which should also be treated at the time of diagnosis)
If you’ve had GBS in a prior pregnancy on its own and without an affected baby or other risk factors then this is NOT an indication for intrapartum antibiotics and you should consider screening again in the current pregnancy.
Women planning a homebirth or a birth in a Midwifery Led Unit need to consider that they may not be able to have intrapartum antibiotics in these settings.
There is no evidence to support treatment for GBS before labour starts.
Risk Factors for GBS
Firstly, it’s important to know that it’s perfectly normal for pregnant women to carry GBS. It can be present at any time – in a woman’s first pregnancy or in one or more subsequent pregnancies. The key is to know about it and take action if needed.
There are certain situations which increase the chance that a newborn baby may develop GBS infection. Each of the risk factors shown below increases the risk of GBS infection in a newborn baby:
- Mothers who have previously had a baby infected with GBS – risk increased x 10
- Mothers who have been shown to carry GBS in this pregnancy or GBS has been found in the urine at any time during this pregnancy – risk increased x 4
- Labour starts or membranes rupture before 37 weeks – risk increased x 3
- Where the waters break more than 18 hours before delivery – risk increased x 3
- Intrapartum raised temperature* of 37.8°C or more – risk increased x 3 *If a woman has an epidural, a slightly raised temperature may be of less significance than in a woman with no epidural
- Carrying GBS, combined with one or more clinical risk factor – risk increased x 12
Further information on GBS can be found from the Royal College of Midwives
and on the GBSS UK patient support Group B Strep Support Website
- Birth Plan Scan & Group B Strep Screening£200A vaginal swab test to test for Group B Strep at around 36 weeks of pregnancy for women planning a vaginal birth PLUS a Birth Plan Scan
- Group B Strep Screening£80A rectal and vaginal swab test to test for Group B Strep at around 36 weeks of pregnancy for women planning a vaginal birth.