Important: This is intended as general information only. It may not apply to your specific situation. It is not a substitute for medical advice. If you have a question or concern, please raise it with me at your next appointment or contact me sooner if it's urgent.
GBS – the Group B Streptococcus Bacteria
The Group B Streptococcus bacteria (GBS) is one of the many bacteria that can live in the vagina. As you may be aware, the healthy vagina is full of bacteria, living in harmony with you and each other. Each woman has a slightly different combination of bacteria living in her vagina. About 15% of women carry the GBS as one of their ‘normal’ bacteria. We don’t really know why some women have this bacteria and some don’t, but it is considered normal for the women who carry it. If you have it, it’s just a normal part of you – it’s not because you’ve become infected with it or because someone gave it to you. We can’t get rid of the bacteria from your vagina with antibiotics – even if this works in the very short term, it usually comes back.
Generally speaking, GBS is not a problem for the women who carry it. However, it can be transferred to the baby during labour which is why we worry about it in pregnancy.
Theoretically, any of the many bacteria in the vagina can be transferred to the baby as the baby comes through the vagina into the outside world. This is pretty uncommon and most of the infections are easily treatable. Therefore, we don’t get too worried unless you have had ruptured membranes (waters broken) for a long time or you develop a temperature in labour. GBS is a bit different – it’s still quite uncommon for the baby to be infected but when infection occurs it can be very serious. GBS causes a condition known as Early Onset Neonatal Sepsis which can be such a severe overwhelming infection that it is difficult to treat, even though we know which bacteria is the culprit. Early Onset Neonatal Sepsis can be fatal.
Because this infection is so serious, it’s much better to prevent it than to wait for it happen and then try to treat it. For this reason, I offer a test to all pregnant women between 35 and 37 weeks gestation to see if they carry the bacteria. If you are found to carry the bacteria, I will give you antibiotics in labour to protect the baby. These work by crossing the placenta and getting into the baby’s blood stream so that the baby is already protected by the time it comes through the vagina. This is pretty easy to do – it just involves a dose of antibiotics into a vein on the back of your hand every few hours while you are in labour. It doesn’t mean that you have to be attached to an IV line (‘drip’) in the meantime and it won’t restrict what else you do in labor. It’s a tiny intervention to try to avoid a nasty situation down the track. If you are found to carry the GBS bacteria, I will discuss this with you in more detail.