Have you heard of Group B Strep?
Group B Strep is a totally new one on me. I only learned about it recently when it came up in a couple of online pregnancy conversations I was involved in and I realised I needed to learn more.
Referred to as Group B Streptococcus, Group B Strep or GBS, it is a normally occurring bacterium that up to a third of all men and women carry in their intestines without symptoms and roughly a quarter of women of childbearing age carry in their vagina at any one time. It is an organism that lives on another without harming it. For most women there are no symptoms of carrying group B strep bacteria.
However, where Group Strep B can become problematic is when the bacteria can pass from a labouring woman to her baby. It is the most common cause of life-threatening infections (sepsis, meningitis, pneumonia) in newborn babies. 90% of early onset Group B Strep infection is preventable by treating mothers with IV antibiotics in labour.
What are the chances of my baby developing a Group B Strep infection?
I don’t have any data for Ireland but the following data from the Group B Strep Support charity in the UK are estimates of the chances a baby in Britain will become infected with Group B Strep if no preventative measures are taken and no other risk factors are present:
1 in 1,000* where the woman is not known to be a carrier of GBS;
1 in 400 where the woman is carrying GBS during the pregnancy;
1 in 300 where the woman is carrying GBS at delivery; and
1 in 100 where the woman has had a previous baby infected with GBS.
*This is a broadly accepted estimate of the number of GBS infections in newborn babies that would occur if no preventative intravenous antibiotics in labour are given and this estimate has been used throughout this document. Recent UK research suggested this may be a serious underestimate of the incidence of GBS infection in newborns, which could be as high as 3.6 per 1,000.
The data is a good indicator for Ireland because the UK adopt the same treatment approach as us.
This is most likely reason that I had never heard of Group B Strep before – it is not routinely tested for in Ireland or in the UK, so it doesn’t come up in antenatal care or literature. Irish and UK hospitals adopt a risk factor approach to treating Group B Strep so IV antibiotics during labour will be recommended if:
- You carry Group B Strep in your body
- You’ve had a previous baby infected with Group B Strep
- Your waters have released for more than 18 hours
- Your labour starts before 37 weeks
- You have a temperature in labour
- Multiple pregnancy
- Your baby’s heart rate is high throughout labour
It is worth noting that 40% of babies that develop Group B Strep have no risk factors. Another additional risk to bear in mind is that many Irish maternity hospitals routinely break a labouring woman’s waters. This carries potential risks to the baby if a mother is carrying Group B Strep but has not been tested. If you have listed that you’d prefer not to have artificial rupture of membranes (ARM) in your birth preferences, it could be worth mentioning the risk factor of passing on an undiagnosed Group B Strep to your newborn if you come up against resistance.
Other countries including the US and Australia test routinely in late pregnancy for Group B Strep.
How do I know if I have Group B Strep during pregnancy?
A vaginal or rectal swab can be taken during pregnancy. The best time for this to be taken is in late pregnancy between 35 – 37 weeks. A positive swab result for Group B Strep means that a woman is colonised with Group B Strep at the time the swab was taken, not that she or her baby will become ill.
What happens if I test positive for Group B Strep in later pregnancy?
Group B Strep colonisation is normal and does not require a women being treated with antibiotics. Preventing Group B Strep infection in newborn babies is the important part, so the time when antibiotics are effective against infection is when they are given intravenously to a pregnant woman whose baby is at raised risk of developing Group B Strep as soon as possible once her labour has started.
Research shows that the risk factor approach to preventing Group B Strep infection in newborn babies, as currently adopted in Ireland and the UK, could prevent up to 6 out of every potential 10 cases. Research has also shown that adopting the US and Australian model, whereby low-risk women are sensitive tested routinely in later pregnancy, combined with offering antibiotics in labour to women at high-risk could prevent over 8 out of every potential 10 cases.
Can I ask to be tested or can I do a home test kit if I’d like to?
If you’d like to, have a chat with your midwife or consultant at your next appointment about testing for Group B Strep so you can make an informed decision about IV antibiotics in labour. If testing is not available you can purchase a private test you can do at home but do check with your caregiver before purchasing the test if they will accept the results of a privately done test because they’re not cheap! Some women under the private care of a consultant do get tested however the test is processed in the hospital’s public lab so all mothers should have access to this test.
But I don’t want to be on antibiotics during labour
Once all the medical facts are presented to you along with the pros and cons of treatment, it is totally up to you to make an informed decision about whether to accept treatment or not. Not every pregnant mother who finds out she is carrying Group B Strep will want intravenous antibiotics in labour. You may decide not to have them unless there are other additional risk factors. It is worth noting that only a small percentage of babies born to mothers carrying Group B Strep at delivery will actually develop Group B Strep infection. You have all of the information, it’s up to you to decide what you think is best for you and your baby. If you do decide against antibiotics in labour, doctors recommend that it would be prudent for the baby to be observed by trained staff for at least 24 hours.
Signs of Group B Strep infection to look out for after your baby is born
- If your baby is unwell due to early onset GBS it is likely to show up in the first 12 – 24 hours.
- Ongoing grunting of your baby.
- Not feeding well
- Seems lethargic
- High or low temperature
- High or low heart rate
- If you have any worries about your baby’s wellbeing speak to a midwife on the postnatal ward.
There’s a lot of information there and it’s a huge amount to digest particularly if you’ve never heard of it before. Please don’t worry, it’s just something that it’s worth being informed about so that you’re prepared. I know I initially thought that it sounded like just one more unnecessary intervention but then I heard from a few Irish mothers who had passed Group B Strep on to their babies and I quickly realised that if I tested positive, given the choice, I would much much prefer for me to be on IV antibiotics for 20 minutes a dose rather than have my tiny new baby on an IV and away from me when he arrived, rather than in my arms where he should be. As with all medical decisions, it’s very much a personal choice.
Weigh it up, see what you think. I know the first thing that will pop into people’s heads is the impact of the antibiotics versus infection risk but read up and make a judgement call. All the power is in your hands once you’ve all the information you need.
There is a huge amount of information on the Group B Strep Support website with a fantastic FAQ section including questions that address home birth, water birth, breastfeeding, natural alternatives, sweeps, ARM, inductions and cow’s milk intolerances to name but a few.
This article from evidencedbasedbirth.com also pulls together all of the current research on Group B Strep: Group B Strep in Pregnancy: Evidence for Antibiotics and Alternatives.