Group B streptococcus, or GBS for short, is one of many different bacteria that normally live in our bodies.
GBS is usually found in the intestines or lower genital tract, and is harmless in most healthy adults.
Around 30% of pregnant women are found to be colonised by the bacteria.
GBS can cause serious illness, and even death, in newborn babies who are exposed to the bacteria during birth. For this reason, screening for GBS is recommended at 36 weeks pregnancy, and treatment is offered to women who have a positive result.
It’s important to know the risks of having GBS, and whether treatment is right for you.
How Do I Get Group B Strep During Pregnancy?
GBS is a common bacterium, which colonises up to 30% of adults, usually without symptoms or side effects. It is most commonly found in the intestines, as part of the normal gut flora.
When GBS infection occurs in adults, it is usually in people with serious medical conditions – such as diabetes, cancer, or liver disease – who have suppressed immune systems. It is also more common in the elderly, and in pregnant women, because of their lowered immunity.
It is important to know GBS is not a sexually transmitted disease.
How Do I Know If I Carry GBS?
You can be a carrier of GBS and not be aware of it, as you won’t show any signs of infection.
The only way to know is to have a swab test done. This usually involves having samples taken from your vagina and anus; the samples are then tested for the presence of GBS.
Depending on where you live, hospitals or doctors might recommend the test for every woman, and some might only offer it to women who are considered high risk.
The bacteria are transient, meaning they can come and go. A positive test at 36 weeks doesn’t necessarily mean GBS will be present when you go into labour. Likewise, a negative swab result doesn’t guarantee GBS won’t be present when you give birth.
What If I Test Positive For Group B Strep?
If your test returns a positive result this simply means you are a carrier of GBS. Not every baby born to mothers with GBS positive results will become ill.
In fact, fewer than 1% of babies who have been colonised by the bacteria during birth (if their mothers weren’t treated) will develop GBS infection.
There are several factors which indicate you are at greater risk of passing on GBS to your baby:
- Waters breaking before week 37
- A urinary tract infection with GBS
- Premature labour (before 37 weeks)
- Amniotic sac broken for longer than 18 hours before birth
- Fever during labour
- Previous baby infected with GBS
Women with GBS who are treated with antibiotics during labour reduce the risk of their babies developing a GBS infection down to around 0.2%.
What Does GBS Infection Mean?
There are two main types of GBS infection in newborns: early onset, and late infection.
Early onset GBS infection occurs in the first week after birth, with the first symptoms usually showing within 12 hours following birth. A study looking at 148,000 babies found almost all of the babies who developed GBS were diagnosed an hour after birth, suggesting the infection begins before birth.
Signs of early onset GBS infection are:
- Abnormal heart rate
- Poor feeding
- Low blood pressure
- Very high, or very low, temperature
- Abnormal breathing rate
Late onset GBS infection is much less common than the early onset type. Symptoms of late onset infection begin 7 or more days after birth, and are usually signs of meningitis with septicaemia.
If you notice any of the following symptoms, with fever and drowsiness, seek urgent medical assistance:
- Irritable behaviour; baby doesn’t like to be held or moved
- High pitched crying, whimpering or moaning
- Arching back
- Bulging fontanelle
- Floppiness, or stiffness with jerky movements
- Staring, blank expression
- Difficult to wake or rouse
- Pale skin which has blotches, or appears blue
- Rash on any part of the body
- Red or purple spots that do not fade when pressed (septicaemia, which is blood poisoning).
What Is The Treatment For GBS?
There are two approaches to managing GBS in pregnancy and labour:
- Universal approach: treat all GBS positive women with antibiotics every 4 hours during labour, starting more than 4 hours before birth. Research has shown antibiotics are more effective at preventing GBS infection in newborns if given 4 or more hours before birth.
- Risk-based approach: treat women with antibiotics only if they have any risk factors (GBS in urine, previous baby with GBS infection, premature labour, waters broken longer than 18 hours).
The universal approach effectively means giving antibiotics to 200 women to prevent 1 case of GBS infection in babies.
The most-commonly used antibiotic for treating GBS during labour is penicillin, which crosses the placenta rapidly and prevents the bacteria from growing in your baby.
The risks of penicillin treatment are:
- Allergic reaction to penicillin. This is rare, but severe reactions are estimated to be 1 in 10,000 and 1 in 100,000 for a fatal reaction
- Mothers and babies are more likely to have yeast infections following the treatment.
- Use of antibiotics can increase the chance of other life-threatening infections such as sepsis and E. Coli, due to antibiotic resistance.
- Antibiotics don’t prevent infection in almost 30% of cases.
- The short and long-term effects on the baby’s gut microbiome are unknown.
You can read more about the risks and benefits of antibiotics during labour here.
Are There Alternative Treatments?
Unfortunately there is limited evidence available for other methods of treatment for GBS. This is mainly because intravenous antibiotics became routine practice over twenty years ago. Most reports of successfully converting positive GBS results to negative are anecdotal.
Garlic is well known for having an active antibacterial component called allicin. Research has shown allicin, in extract form, will kill GBS within 3 hours (in petri dish conditions).
Supporters of the garlic method suggest inserting half a clove of garlic into the vagina and leaving overnight. This needs to be done for 8 days before having the test.
GBS recolonises the vagina easily so a negative result doesn’t guarantee you will not have GBS present during the time of labour. Little is known about the effects of garlic on other good bacteria, or whether it increases the risk of premature rupture of membranes.
The use of probiotics is another alternative method of treatment women have used for GBS infections. Probiotics are well known for promoting good bacteria in the gut, which can then influence the flora in the vagina.
Good sources of probiotics are fermented foods, such as kefir, yoghurt, and sauerkraut. Probiotic supplements can also be taken orally, and some women insert a source of probiotics into the vagina.
Other alternative treatments include:
- Apple cider vinegar bath: 1/4 cup of apple cider vinegar added to bath water, three times weekly
- Echinacea and Astragalus herbal tincture
- Vitamin C: whole food sources are best, such as rose hip or elderberry
Can GBS Be Prevented?
Due to the transient nature of GBS it is hard to know if, or when, it will be present in your body.
The best approach to preventing GBS is to focus on restoring healthy bacteria in both the gut and the vagina. This means taking a holistic approach to your pre-pregnancy health, investing in a healthy and nutritious diet, and avoiding processed foods before becoming pregnant.
During pregnancy, your immune system is naturally suppressed, so it’s important to focus on self-care, and avoid foods and environments which further tax your body.
This includes eating plenty of pre- and pro-biotic-rich foods, to help ‘feed’ and grow good bacteria. This also promotes a low pH environment in your gut and vagina, discouraging the unwanted bacteria like GBS from developing.
Stress during pregnancy can have negative effects on gut health. Studies have shown mothers experiencing chronic stress during pregnancy have higher levels of disease promoting bacteria, and lower levels of beneficial bacteria.
During labour, you can reduce the risk of potential GBS infection by avoiding any procedures which involve internal examinations or insertion into your vagina.
Bacteria are usually found in the lower part of the vagina, and can be moved upwards towards the cervix by:
- Vaginal examinations during labour
- Membrane stripping/sweeping
- Induction (requires internal exams and possible insertion of medication)
- Internal monitoring.
I’m Not Sure I Want To Do The Test
As with all aspects of pregnancy and birth, there are overall risks and individual risks. It is important to have all the information relevant to you and your personal health situation, in order to decide what is best for you and your baby.
If you prefer not to have the test, it’s important to discuss this with your care provider, especially if you have any of the risk factors for GBS infection. You might decide to take preventative measures during pregnancy, to lower the chances of GBS colonisation occurring.
I’m GBS Positive But Don’t Want Antibiotics
If you are GBS positive and prefer to avoid antibiotics, discuss your options with your care provider. If your baby is born full term (after 37 weeks) and is doing well, and you had no other risk factors (uterine infection, waters broken for longer than 18 hours), then it is unlikely your baby will have acquired an infection.
Your baby can be observed for 48 hours to make sure symptoms of GBS don’t develop; the C-reactive protein test can be done if necessary. This indicates whether an infection is present in the baby and, if the result is negative, your baby can avoid unnecessary antibiotics.
It’s important to have skin to skin contact immediately after birth, so your baby is colonised by your good bacteria. This helps prime his immature immune system and avoids mother and baby separation. Babies are more likely to be colonised by ‘bad’ bacteria if they are separated from their mothers immediately after birth, or are born by c-section.
The decision to test for, and treat, GBS is a personal one. Although GBS infection in newborns is serious, there are risks as well as benefits to treatment. It is important to have information relevant to your risk factors, in order to make an informed choice.
Preventing GBS colonisation begins with pre-conception health care, and continues during pregnancy. While this can’t guarantee you will avoid GBS, it might lower your risk factors, and help you to avoid unnecessary treatment.