July is Group B Strep. awareness month & we will be answering some common questions about GBS in this blog!

Content warning: in this blog post we will outline some statistics which touch upon rates of infection and morbidity (illness) and neonatal (baby) death.

What Is Group B Strep (GBS)?

GBS stands for Group B Streptococcus. GBS is part of the normal flora of the gastrointestinal tract. It is a common type of bacteria that lives in the vagina, rectum and intestines of about 20-40% of women. The presence of GBS is known as being a ‘carrier’ or being ‘colonised’ – it does not mean you are infected with it and colonisation can also be temporary. It is important to note that GBS is not a sexually transmitted disease.

How Is GBS Detected During Pregnancy?

It may be detected on a vaginal swab or on a urine sample during pregnancy. In terms of having a swab, best practice to detect GBS is to take one or more swabs from the lower vagina and the rectum to be able to identify colonisation and avoid false negative test results. Many NHS trusts routinely send off a urine sample to be analysed at the initial booking appointment to screen for the presences of a urinary tract infection (UTI), which some people are more susceptible to in pregnancy. You should always be asked for your consent and be provided with an explanation of what the urine test will be looking for. We know from practice that women and birthing people are not being routinely informed that the urine sample may identify bacteria like Group B Strep and what the implications of testing for that are.

Some women and birthing people choose to have a GBS swab done privately, which is something we can facilitate – get in touch if you’d like to know more. 

What Does a GBS Positive Result Mean for You and Your Baby?

If GBS is found in the urine, oral antibiotics are offered to clear the bacteria (even in the absence of any UTI symptoms) as this is considered to be a ‘heavy colonisation’ of the bacteria. If the GBS is picked up on a swab, oral antibiotics are not offered during pregnancy as they do not clear the GBS colonisation from the vagina or intestines. In either case, intravenous (IV) antibiotics are offered 4 hourly when you are in labour to minimise the chance of transmission of the GBS bacteria to your baby, which in rare cases can cause serious infection in newborn babies (more on that later!). If your waters break before you go into labour, you will be offered immediate antibiotics and an induction of labour – again, the aim is to minimise the chance of the baby picking up the GBS during labour or as they are being born. It is your choice if you want to have these antibiotics or not. Using the BRAIN decision making tool may come in handy here to help you weigh up the pros and cons of antibiotics and/or induction of labour. 

How Likely Is a GBS Infection in Newborn Babies?

Early-onset GBS infection occurs within 24 hours of birth and affects 1:1750 newborns and late-onset GBS infection occurs from 7 days – 3 months following birth and affects 1:2700 babies. The antibiotics offered in labour are only effective at reducing the incidence of early-onset infection, but make no difference to the incidence of late-onset GBS infection. The statistics demonstrate that most babies born to women or birthing people who carry GBS will be unaffected ie. they will be well and not develop a GBS infection. For a small proportion of babies GBS can cause serious infection and in very rare cases even death.

The Group B Strep Support website has these figures on babies with a confirmed GBS infection in the UK and Ireland:

Early-onset GBS infection

• 1:1750 or 0.06% babies will develop an early-onset GBS infection
• 1:19 or 5.2% of those infected will die
• 1:14 or 7.4% of those infected will live with a long-term physical or mental disability

Late-onset GBS

• 1:2700 or 0.04% of babies will develop a late-onset GBS infection
• 1:13 or 7.7% of those infected will die
• 1:18 or 12.4% of those infected will live with a long-term physical or mental disability

Why Isn't GBS Screening Routine in the NHS?

Screening for GBS is not routinely offered by the NHS because routine screening has so far not been proven by research to improve outcomes. Given that 20-40% of women are GBS carriers, screening would result in significantly more women and birthing people being offered antibiotics during labour, when they may not need them. Consideration has to be given to routine use of antibiotics when we live in an age of antibiotic resistance and what effect antibiotics have on the newborn baby’s microbiome. We need to make sure that when we use antibiotics they are truly needed.

Does Having GBS Affect Your Choice of Birth Place?

The main issue that can arise with choice of place of birth if you have GBS, is that if you have chosen to have the IV antibiotics during labour, this may or may not be facilitated across all birth settings. There would be no issue receiving the antibiotics on a labour ward, but you would need to check if you would be able to have them if you chose to birth on an alongside midwifery-led unit (a birth centre attached to a hospital), a free-standing birth centre (not physically attached to a hospital) or at home. If your place of birth is restricted due to lack of access to the IV antibiotics, you may wish to weigh up whether the benefits of the IV antibiotics outweigh the risks of birthing on a labour ward if you are otherwise considered ‘low risk’ and have had an uncomplicated pregnancy.

In our experience IV antibiotics are usually out of the question for home birth (that doesn’t mean you can’t choose home birth – but you choose to forgo the antibiotics). Freestanding birth centres may or may not have a policy that supports the use of IV antibiotics specifically for women and birthing people who have GBS. We would recommend finding this out as soon as you can in your pregnancy if you have GBS and wish to use one. Consult with the midwifery manager to see how your choice of using the freestanding birth centre and having antibiotics could be supported. This will help to ensure you can both birth where you wish and make an informed choice as to whether you have IV antibiotics or not. Unfortunately, there does not appear to be a national consensus on the use of IV antibiotics in free standing birth centres so you will find different policies and practices all over the country.

Does GBS Affect How You Can Give Birth?

Having GBS should not affect how you choose to give birth. If you are planning a vaginal birth, you will be advised to have IV antibiotics every 4 hours during labour. This involves having a cannula in your hand or wrist. If you have a caesarean section, antibiotics are not required – unless your waters have broken and / or you have an emergency caesarean during labour. If your pregnancy is otherwise uncomplicated, being a GBS carrier is not a reason to recommend continuous fetal monitoring (a CTG) during labour. Research has shown that the routine use of CTGs in labour in ‘low risk’ women increases the chance of interventions, such as caesarean sections, in labour. 

Do You Have to Have Antibiotics for GBS in Labour?

It is your choice if you want to have antibiotics during labour or not. We know that antibiotics are very effective at reducing the incidence of early-onset GBS infection in newborn babies, but have no impact on late-onset GBS infection. We also know that the incidence of early-onset GBS infection is rare with 1:1750 babies being affected. There is a small risk of allergic reaction to antibiotics, and it is important that your healthcare provider knows if you have an allergy to penicillin. A penicillin allergy is not compatible with the usual antibiotics given for GBS so health care providers will offer a suitable alternative to this.

What Happens After Birth If You Have GBS?

Different hospitals will have different policies, but generally speaking it will be recommended that your baby has some observations after birth. These observations are checking their temperature, heartbeat, breathing rate and general wellbeing. There is no need for them to be separated from you for these observations and having GBS does not affect breastfeeding. The NICE guidelines recommend using clinical judgement to assess if a baby requires observations for 12 hours following birth in the presence of a single risk factor – of which GBS colonisation is classed as one. The likelihood of GBS infection developing after 12 hours is very low. The Royal College of Obstetricians and Gynaecologists (RCOG) advise that babies do not require special observations if they are born at term (>37 weeks), are clinically well at birth and if their mother or birth parent received IV antibiotics more than 4 hours before they were born. Some hospitals may have a policy of routine observations for at least 12 hours for all babies born to mothers or birth parents who carry GBS, regardless of whether IV antibiotics were given or not. 

If you birth at home, your midwives can do some observations on your baby if you wish. If they have any concerns with your baby’s wellbeing, they can refer you to the hospital for a review by a neonatal doctor. Regardless of where your baby is born, if there are ongoing concerns about their wellbeing or any suspicions of infection, they will be reviewed by a neonatal doctor and it may be recommended that they have IV antibiotics. If the baby is otherwise stable, they can remain with you on the postnatal ward, but if it seems like the baby is unwell they may need to be admitted to the neonatal unit for more intense observation and care.

Signs of an unwell baby to look out for include: being unusually floppy, displaying abnormal behaviour (such as inconsolable crying or listlessness), a change in skin colour, rapid breathing, having a temperature above 38 degrees celsius or below 36 degrees celsius that cannot be attributed to environmental factors, lack of interest in feeding or continuous rapid breathing. If you ever have any concerns about your baby, even if you can’t put your finger on it, it is worth getting it checked out.

Will GBS Affect Future Pregnancies?

GBS is transient – meaning that a person may not always be a carrier. If you have been a GBS carrier in a previous pregnancy, you may wish to have a repeat swab in your next pregnancy to see if the GBS is still present. If the swab is negative for GBS between 35-37 weeks in a subsequent pregnancy, then IV antibiotics during labour are not recommended by the NICE guidelines. However, if you have had a previous baby diagnosed with a GBS infection, then NICE recommends IV antibiotics in labour – regardless of the result of a swab or urine test in the current pregnancy.

Got more questions? Interested in independent midwifery care? Want guaranteed access to home birth? Get in touch to arrange an informal chat about what we can offer you.

Further resources

Group B Strep Explained – another fantastic, accessible book from Sara Wickham

Group B Strep Support – a charity providing information about GBS and support for those who have been affected by it