Frequently Asked Questions:
- What is group B Strep?
- Which countries offer sensitive GBS tests to pregnant women?
- How many people carry GBS?
- How can people become carriers of GBS?
- Are the tests for GBS colonisation reliable?
- I’ve been told GBS comes & goes so often it’s not worth testing for
- I’ve been offered an NHS test for GBS carriage – is that OK?
- Do I have to do the GBS test between 35 and 37 weeks of pregnancy?
- What happens if I get a negative ECM or PCR test result?
- Do I need antibiotics as GBS was found on a vaginal or rectal swab?
- I carry GBS in my vagina. Does my partner need to be tested?
- I have vaginal symptoms – are these caused by GBS?
- Will antibiotics get rid of GBS colonisation from my vagina during pregnancy?
- Should I take antibiotics before I get pregnant to get rid of the GBS?
- Do I need antibiotics if GBS is found in my urine?
- I had a positive result early in my pregnancy. Should I be tested again?
- Should I be tested regularly for GBS?
- I carried GBS in my last pregnancy – my baby was fine. Do I need IV antibiotics this time?
- What are the chances of my baby developing a GBS infection?
- Must I have intravenous antibiotics if I’ve had a positive result during this pregnancy?
- If I have the IV antibiotics in labour, do I have to be attached to a drip the whole time?
- What are the potential risks of antibiotics?
- Antibiotics – more harm than good?
- I don’t want antibiotics in labour – are there natural alternatives?
- Is vaginal disinfection an alternative to intravenous antibiotics in labour?
- I worry I will not get 4+ hours of IV antibiotics before my baby is born.
- I am at raised risk of premature labour; should I take long-term antibiotics?
- What are the signs that GBS is affecting my unborn baby?
- Should I be induced, with the IV antibiotics starting as I’m induced?
- Will a Caesarean prevent GBS infecting my baby?
- If I’m having a Caesarean, do I need antibiotics before it against GBS infection in my baby?
- Are membrane sweeps safe for women who carry GBS?
- GBS and artificial rupture of membranes
- I want a water birth
- I want a home birth
- I want to breastfeed my baby
- My baby’s at higher risk of developing GBS infection – what should happen after birth?
- What about late-onset GBS infection?
- Is GBS infection linked with cow’s milk intolerance?
- GBS and Swine Flu
What is group B Strep?
Firstly, it is important to know that carrying GBS is perfectly normal and natural. It is found as part of the normal gut flora in up to a third of people (men and women), and colonises the vagina in roughly a quarter of all women. Although GBS can be passed through sexual contact, it is not a sexually transmitted disease, and carrying the bacterium is not associated with any health risks or symptoms to the carrier. It is also relatively common amongst adults who have never had any sexual contact.
Carrying GBS in the gastrointestinal tract or vagina does not require treatment (however, the presence of GBS in the urine/ blood usually signifies a GBS infection, which may require antibiotics – your doctor can advise further). More information on GBS can be found by clicking here.
If you know you carry GBS during pregnancy, it is good to know. If GBS is found during your pregnancy, you should be offered intravenous antibiotics in labour which massively reduce the risk of your newborn baby developing group B Strep infection. Most pregnant women in the UK don’t know if they carry GBS so can’t take preventative measures.
Which countries offer sensitive GBS tests to pregnant women?
Countries which we understand offer sensitive tests for GBS to women during pregnancy include: Australia, Argentina, Barbados, Belgium, Brazil, Canada, Chile, Czech Republic, Dubai, France, Germany, Hong Kong, Italy, Japan, Kenya, Lithuania, New Zealand, Oman, Poland, Spain, Slovenia, Switzerland and the USA.
How many people carry GBS?
GBS is a normal bacterium which is carried by up to 30% of adults, most commonly in the gut, but for up to 25% of women, in the vagina too.
Not everyone carries GBS and pregnancy does not ‘bring it on’ or cause a ‘flare-up’ of group B Strep. It can be passed from mother to baby during labour and, although this causes no problems for most babies, for a small number it can be deadly, causing blood poisoning, pneumonia and meningitis.
How can people become carriers of GBS?
GBS may be passed from one person to another through skin to skin contact, for example, hand contact, kissing, close physical contact, etc. As GBS is often found in the vagina and rectum of colonised women, it is commonly passed through sexual contact.
There are no known harmful effects of carriage itself and, since the GBS bacteria do not cause genital symptoms or discomfort, GBS carriage is not a sexually transmitted disease, nor is GBS carriage a sign of ill health or poor hygiene.
No-one should ever feel guilty or dirty for carrying GBS it’s normal.
Because GBS may be passed from one person to another by skin to skin contact, everyone whether they know they carry GBS or not should wash their hands properly and dry them properly before handling a newborn baby.
Are the tests for GBS colonisation reliable?
The standard direct plating tests available are not very reliable when they give a negative result – they give a falsely negative result up to 50% of the time when they should be positive! On the other hand, if you get a positive conventional test result, that is very reliable. See Which Test for GBS?
Any positive result (direct plating, ECM or PCR) means you should be offered intravenous antibiotics as soon as possible after the start of your labour or membrane rupture to protect your baby from GBS infection.
[GBSS fully endorses the availability of reliable antenatal GBS testing but has no links to nor receives any money from any laboratory. Indeed we hope many laboratories will offer the ECM test and, as they do, we'll provide details of their service here.]
I’ve been told GBS comes & goes so often it’s not worth testing for
Well, that’s simply wrong. Research has shown that, whatever the result of a sensitive test for GBS (ideally ECM), then your GBS status is hugely likely to be the same for the next 5 weeks. After that, the predictiveness wanes a bit – though it doesn’t plummet like a stone – which is why when testing is done, it’s recommended at 35-37 weeks of pregnancy.
Some of the confusion of UK health professionals may stem from the fact that the standard swabbing method (high vaginal swabs, or HVS) and the standard culture method (direct plating) used by the NHS were not designed specifically for detecting GBS and are not great at finding it. Research has found that using high vaginal swabs and the direct plating method of culture will miss up to 50% of the women carrying GBS at delivery. Clearly a positive test result obtained by this method is reliable, but if you get a negative result, you can’t be sure it’s because the GBS isn’t there or whether it’s because the test simply didn’t detect it.
I’ve been offered an NHS test for GBS carriage – is that OK?
Not all tests that are used to detect group B Strep carriage are as good as each other, unfortunately. A positive test result is hugely reliable (tests tend not to find something that isn’t there), but a negative result can be less so. It’s important to find out which test you’re being offered – the standard ‘non-specific’ test or a GBS-specific Enriched Culture Medium (or ECM) test – if you’re health professional isn’t sure which it is, then it’s likely to be the non-specific test.
Read more about the different tests by clicking here.
For information about where you can obtain the ‘gold standard’ ECM test for group B Strep carriage, both on the NHS and privately, click here.
Do I have to do the GBS test between 35 and 37 weeks of pregnancy?
No. However, 35-37 weeks is suggested for testing, as this has shown to be a highly predictive indicator of whether you will be carrying when you go into labour. If taken during this time, the ECM test has been found to be a reliable predictor of your carriage status at delivery.
If the test is taken earlier than 35 weeks, then the chance that your carriage status has changed upon delivery increases (ie that you have either picked up GBS carriage, or that you have lost it). After 35 weeks, research has shown that it is more unlikely that the carriage status will change.
If the tests are taken later than 37 weeks, they will still give you an accurate indication as to your carriage status at delivery, however, there is a chance that your results will not be ready when you go into labour! It would be a shame to do the test then get the results after your baby is born!
So the 35-37 weeks window is suggested as being potentially the best time to test – having said that, it won’t suit everyone!
What happens if I get a negative ECM or PCR test result?
A woman who has a negative ECM (Enriched Culture Medium) or PCR (Polymerase Chain Reaction) test result within 5 weeks of delivery does NOT need to be offered intravenous antibiotics in labour to prevent GBS infection in her baby (but antibiotics may be indicated for other reasons) . Research shows that, if performed within 5 weeks of delivery, an ECM test giving a negative result is 96% predictive of GBS not being carried at delivery (4% of women acquired carriage between testing and delivery) so the risk of acquiring carriage between doing the test and giving birth is very small.
If a woman has not had an ECM or PCR test result OR the less reliable conventional test has been negative during the pregnancy, she should be offered intravenous antibiotics from the onset of labour if one or more risk factors (listed at Risk Factors for GBS) are present.
A woman who has previously had a baby who developed GBS infection should ALWAYS be offered intravenous antibiotics in subsequent pregnancies, from the onset of labour or membrane rupture until delivery, regardless of any test results.
And a woman who has had any positive test result (from the urine, vagina or rectum) during the current pregnancy should also be offered intravenous antibiotics from the onset of her labour or membrane rupture until delivery.
Do I need antibiotics as GBS was found on a vaginal or rectal swab?
If group B Strep has been found during your current pregnancy from a vaginal or rectal swab, no treatment is beneficial during pregnancy until labour starts, when you should be offered intravenous antibiotics*. Antibiotics have been shown to be highly effective at preventing GBS infection in newborn babies when they’re given as soon as possible once labour has started and at regular intervals until the baby is born. This dramatically reduces the risk of GBS infection in a newborn baby. To find out more about our medical panel’s recommended preventative medicine click here.
*All national guidelines published in the UK recommend that Mum should be offered intravenous antibiotics in labour if GBS has been detected during the current pregnancy.
I carry GBS in my vagina. Does my partner need to be tested?
No. Colonisation with GBS is normal and does not need treatment. A third of the adult population carries GBS, without symptoms – you don’t need to be tested for it, nor do you (or he) need antibiotics for it. GBS is not a sexually transmitted disease. Carrying GBS is not a disease at all!
I have vaginal symptoms – are these caused by GBS?
A GBS positive result from a vaginal swab means the woman’s vagina was colonised with GBS when the swab was taken. GBS carriage is asymptomatic – it is not associated with symptoms. Just because GBS is isolated from a swab taken to investigate vaginal symptoms does not mean GBS is the cause of those symptoms. We know of no publication that convincingly correlates GBS carriage with any vaginal symptom, and people have specifically looked into this.
Antibiotics for GBS carriage are not indicated. No antibiotics tested so far have been shown to eradicate GBS reliably from the body so, even if antibiotics clear the GBS colonisation of the vagina (and they may not), recolonisation from the intestines will occur. The time when antibiotics have been proven to be effective against GBS infections in babies is when they are given intravenously to the mother once her waters have broken or as soon as labour has started and at intervals until delivery.
Will antibiotics get rid of GBS colonisation from my vagina during pregnancy?
Antibiotics won’t necessarily get rid of colonisation in the vagina and, even when they do, they will do so only temporarily – recolonisation will occur. Evidence shows taking antibiotics before labour does not reliably eradicate GBS carriage – and there’s no evidence that it reduces the incidence of GBS infection in newborn babies either. Studies have shown no substantial difference in GBS carriage at delivery between women treated with antibiotics during pregnancy and those not treated. In one study, nearly 70% of colonised women treated with antibiotics for 12 to 14 days during the third trimester (28 to 40 weeks of pregnancy) were colonised three weeks later and again at delivery.
Antibiotics during pregnancy for GBS carriage are not indicated. GBS cultured from a vaginal swab show the vagina is colonised with GBS, not infected. No antibiotics tested so far have been shown to eradicate GBS reliably from the body so, even if antibiotics clear the GBS colonisation of the vagina (and they may not), recolonisation from the intestines will occur. Evidence shows taking antibiotics neither gets rid of GBS carriage nor reduces the incidence of GBS infection in newborn babies. Antibiotics have been proven to be highly effective at stopping GBS infections in newborn babies when given intravenously to the pregnant woman as soon as her membranes have ruptured or labour has started.
Should I take antibiotics before I get pregnant to get rid of the GBS?
No antibiotics tested so far seem able to do this reliably. Antibiotics may temporarily eradicate vaginal colonisation with GBS, but colonisation in the intestines will remain and recolonisation of the vagina will occur.
Do I need antibiotics if GBS is found in my urine?
Generally yes as urine is normally sterile inside the bladder. However, not all GBS detected in the urine means an infection is present, particularly when the level detected is low – sometimes it is just that the urine has picked up some of the bacteria from vaginal GBS carriage on its way out of the body.
Treatment for GBS found in the urine depends on the level of GBS found in the urine and on whether or not Mum has any symptoms. When detected during pregnancy:
- GBS in the urine ≥ 10^5 cfu/ml with or without Mum having symptoms of a urinary tract infection (for example, frequent or painful urination or fever) – this is considered as bacteriuria and treated with oral antibiotics. Mum should also be offered intravenous antibiotics when she goes into labour.
- GBS in the urine ≥ 10^4 cfu/ml with Mum have symptoms of a urinary tract infection – this is treated with oral antibiotics. Mum should also be offered intravenous antibiotics when she goes into labour.
- GBS in the urine 10^4-10^5 cfu/ml with Mum having no symptoms of a urinary tract infection – usually the midstream stream urine test (preferably with labia separated) is repeated. If the same level of GBS is still present, then treatment will be considered. Mum should also be offered intravenous antibiotics when she goes into labour.
- GBS in the urine ≤ 10^3 cfu/ml or less with Mum having no symptoms of a urinary tract infection – this is considered to be contamination and no treatment is offered. Mum should be offered intravenous antibiotics when she goes into labour.
When treatment is recommended for GBS bacteria in the urine during pregnancy, oral antibiotics are given, usually for 5 days. The urine should be retested 7-10 days after finishing the antibiotics and treatment repeated if necessary until the urine tests come back clear.
Treatment for a urine sample which detects the growth of GBS in the urine ≥10^5 cfu/ml, whether you have symptoms of a urine infection or not, is important since, if left untreated, such infections can cause kidney damage and have been linked to preterm labour.
GBS detected from a urine sample or from a vaginal or rectal swab at any level during pregnancy means Mum should be offered intravenous antibiotics once labour has started.
I had a positive result early in my pregnancy. Should I be tested again?
If you have had a positive GBS test result (from the vagina or rectum) during the current pregnancy, and no further tests, you should be offered intravenous antibiotics from the onset of labour or membrane rupture until delivery (antibiotics are usually recommended if the positive result was from the urine – click here).
However, if the positive result was early in your pregnancy, you may have lost carriage by the time your baby is born. If you want to find out whether you are still carrying GBS, you can have a sensitive test at 35-37 weeks. If the sensitive test result is negative, then intravenous antibiotics are probably not indicated, since research shows that a sensitive test giving a negative result within 5 weeks of delivery is highly predictive of the mum not carrying GBS at delivery. The risk of acquiring carriage between doing the test and giving birth is very small.
Should I be tested regularly for GBS?
No. If you have had a positive test result for GBS at any time during your current pregnancy, you should be offered intravenous antibiotics from the start of your labour, until delivery.
The conventional test available on the NHS is unreliable – it misses up to 50% of GBS carriers. There is a reliable test but this is not available from most NHS hospitals, although it is available from two private laboratories which offer a postal service. See Which Test for GBS?
And if you get another positive result from the conventional test, all it tells you is that you are still carrying GBS. If it gives you a negative result, all it tells you is you may not be still carrying GBS (but remember the negative test results aren’t very reliable). Neither of these results should make any difference to your being offered intravenous antibiotics in labour.
I carried GBS in my last pregnancy – my baby was fine. Do I need IV antibiotics this time?
GBS can quite naturally come and go from the vagina so the bacteria can be there one month and not the next … and back again at some other time (though research has shown that, using sensitive tests, the results are highly predictive of colonisation status for around five weeks). There is currently no good data that can predict carriage of GBS over periods of a year or more. However, since there may be some increased chance of a woman carrying GBS in a pregnancy if GBS has been isolated previously, it is the view of our medical panel that, if possible the pregnant woman should be offered a reliable (ECM or PCR) test at 35-37 weeks of pregnancy to establish whether she is still carrying GBS. If the test is positive, then she should be offered intravenous antibiotics as soon as possible once labour has started.
If a reliable ECM or PCR test result is not available and labour starts after 37 weeks of pregnancy, then the view of our medical panel is that previous carriage status should be treated as an additional risk factor (increasing the risk of a baby developing GBS infection where preventative antibiotics in labour are not given from an estimated 1 in 1,000 in the general population, to approximately 1 in 500 for a woman whose current GBS status is unknown, but where GBS was isolated before the current pregnancy). Our medical panel’s view is that the ‘previous carrier’ risk factor alone is insufficient to recommend offering intravenous antibiotics in labour against GBS infection in the baby, unless another clinical risk factor was also present.
What are the chances of my baby developing a GBS infection?
The following are estimates of the chances a baby in Britain will become infected with GBS 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.
If a woman who carries GBS is given antibiotics during labour through delivery in accordance with our medical advisory panel’s recommendations at Prevention, the baby’s risk is reduced significantly.
- 1 in 8,000 where the mother carries GBS during pregnancy;
- 1 in 6,000 where the mother carries GBS at delivery; and
- 1 in 2,200 where the mother has previously had a baby infected with GBS.
The vast majority of pregnancies can be managed so that babies are protected and born free of GBS infection.
Must I have intravenous antibiotics if I’ve had a positive result during this pregnancy?
If you have had any positive GBS test result from the vagina or rectum during the current pregnancy, you should be offered intravenous antibiotics from the onset of labour or membrane rupture until delivery. However, you may choose not to have them if there are no additional risk factors – only a small percentage of babies born to colonised mothers will develop GBS infection. However, if you decide against antibiotics, it would be prudent for the baby to be observed by trained staff for at least 24 hours (and ideally for 48 hours). If the positive test was from the urine, this means that the GBS was more invasive, and so antibiotics will be recommended even if a vaginal swab is subsequently negative.
If I have the IV antibiotics in labour, do I have to be attached to a drip the whole time?
No, the antibiotics are given intravenously through a cannula (usually in the back of your hand). They’re given either by slow injection over 5-10 minutes or so, or through a drip which can take 20 minutes or so. Once the antibiotics have been given, the cannula is plugged and you are then able to move around as you wish, until the top up dose is due (4 hourly for Penicillin, 8 hourly for Clindamycin).
What are the potential risks of antibiotics?
Taking antibiotics should not be done lightly – they can have side effects that need to be considered in relation to the potential benefits and it is important that you tell your health professionals if you have ever had an allergic reaction to penicillin or any other antibiotic.
Although good data is hard to find on this subject, the generally quoted estimated risks for penicillin are:
- 1 in 10 of the mother developing a mild allergic reaction, such as a rash;
- 1 in 10,000 of the mother developing a severe allergic reaction (anaphylaxis); and
- 1 in 100,000* of the mother developing fatal anaphylaxis, resulting in her death.
And severe complications can occur in the unborn baby even when the anaphylaxis developed by the mother is not life threatening, although this risk is probably overstated.
*Although often quoted, these figures are generally accepted as being a significant over-estimate of the risk – a recent paper stated that, in the US between 1997 (the year after the CDC recommended intravenous antibiotics in labour for women whose babies were at higher risk of developing GBS infection) and 2001, an estimated 1.8 million women were given penicillin in labour and no deaths occurred, so an estimate of a 1 in 100,000 risk of death from penicillin anaphylaxis is likely to be an over-estimate. The prevention of neonatal group B streptococcal disease. MR Law, G Palomaki, Z Alfirevic, R Gilbert, P Heath, C McCartney, T Reid, S Schrag on behalf of the Medical Screening Society Working Group on GBS Disease. J Med Screen 2005;12:60-68.
Whenever antibiotics are taken, there are always risks of antibiotic resistance developing. When antibiotics are given to pregnant women, this could affect the mother and her baby. When antibiotics are given around birth and in the early weeks of life, there is the chance they may increase the likelihood of the baby developing allergies. Although a lot of press space is given to this, data is unfortunately lacking on whether it’s the giving of antibiotics that causes the allergies, or whether there are other reasons (for example, genetics, environment, disease, etc.). This is yet another area where more research is needed!
Bearing all this in mind, you need to weigh up whether you consider the risks are acceptable in comparison with the potential benefits and, if so, in what circumstances you would want to be offered antibiotics.
Antibiotics – more harm than good?
Sometimes we’re asked whether antibiotics in labour against GBS infection in the newborn baby do more harm than good. The source of concern is often an article published in 2008 in the Lancet, about the ORACLE II trial. This reported the long-term effects of antibiotics given to women in threatened preterm labour. Their babies were followed up to age 7. The study found that low-dose, broad spectrum, oral antibiotics for up to ten days produced no benefits and were associated with about double the risk of the baby developing cerebral palsy for reasons that are not fully understood. In contrast to the regime used in the ORACLE II trial, women given antibiotics as preventative medicine against GBS infection in their newborn baby are given high-dose, narrow-spectrum (usually penicillin), intravenous antibiotics at 4 hourly intervals from the start of labour until the baby is born (so for hours not days). This has been shown to reduce the risk of early onset GBS disease by about 90%, without any known long-term side-effects on the baby.
There has been a lot of publicity recently about the inappropriate and excessive use of antibiotics (sparked by Prof Dame Sally Davies DBE, Chief Medical Officer, England – click here). We at GBSS are well aware of the risks of excessive use of antibiotics and have worked hard to stop misconceptions which result in their being given inappropriately – for example, in an erroneous attempt to eradicate carriage, or in a labour following a positive result from a previous pregnancy where the baby was unaffected.
Research has shown that intravenous antibiotics (ideally penicillin), given in labour to women whose babies are at higher risk of developing GBS infection, is highly effective at reducing the risk of GBS infection in newborn babies, without any known long-term side-effects on the baby, and no apparent tendency to increase antibiotic resistance. Indeed, GBS has remained sensitive to penicillin for over 60 years.
I don’t want antibiotics in labour – are there natural alternatives?
All of the information we supply is based upon medical research and/or the advice of our highly regarded medical advisory panel.
The members of our medical advisory panel are not persuaded that any therapy other than antibiotics in labour is effective in preventing early onset GBS disease.
One question we have been asked a lot recently is whether raw garlic, inserted into the vagina, will reduce the likelihood of GBS infection in a newborn baby. There is no good evidence that garlic will prevent GBS colonisation and, since the reservoir for GBS colonisation is the gut, garlic vaginally won’t help with that at all
Unfortunately, although there is much discussion on this subject, particularly online, there simply are no natural, homeopathic or alternative medicines for which
there has been good research and proof that they are effective at
preventing group B Strep infection in newborn babies. It this changes, we’ll issue an update.
Is vaginal disinfection an alternative to intravenous antibiotics in labour?
The idea that vaginal disinfection at the time of labour may eradicate GBS colonisation in the vagina (it would not affect rectal colonisation) has been investigated, particularly in Scandinavian countries. The advantages are that the potential risks associated with antibiotics are avoided whilst, at the same time, the vaginal disinfection may reduce neonatal colonisation with GBS. However, reduced neonatal colonisation would have no impact on the majority of babies who develop early onset GBS infections, since these babies are usually infected or colonised before they come through the birth canal. A study of over 5,000 labouring women found that using maternal chlorhexidine vaginal wipes during labour and neonatal chlorhexidine wipes did not reduce death in the mother or baby, or sepsis in the baby. It is also questionable how acceptable using chlorhexidine would be to pregnant women – it is not an innocuous substance and could potentially be harmful to the baby, particularly if the waters have broken or the baby is preterm.
The members of our medical advisory panel are not persuaded that any therapy other than antibiotics in labour is effective in preventing early onset GBS disease.
I worry I will not get 4+ hours of IV antibiotics before my baby is born.
A very small study1 showed giving intramuscular penicillin eradicated GBS colonisation for at least 6 weeks in 75% of women known to carry GBS. So far, this very small study (50 of 78 women received intramuscular antibiotics) has not been repeated, so it is difficult to give advice based upon this data.
For women known to carry GBS where it is not expected that the intravenous antibiotics can be given for at least 4 hours before delivery, an intramuscular injection of 4.8 MU (2.9 g) of Penicillin G at about 35 weeks of pregnancy may be useful in addition to intravenous antibiotics given from the onset of labour or membranes rupturing until delivery to try to eradicate GBS colonisation until after delivery.
Regardless of whether you have intramuscular antibiotics to try to eradicate GBS colonisation, it is recommended that all women in higher risk categories be offered intravenous antibiotics from the onset of labour or waters breaking, plus at 4 hourly intervals until delivery.
There are downsides of intramuscular penicillin – the injection is painful, there is a small risk of an allergic reaction and of antibiotic resistance developing (see below). These risks are repeated with the intravenous antibiotics given in labour.
For intramuscular antibiotics, there are no known alternatives to penicillin for penicillin-allergic women.
1(Bland ML, Vermillion ST, Soper DE. Late third-trimester treatment of rectovaginal group B streptococci with benzathine penicillin G. Am J Obstet Gynecol 2000 Aug;183(2):372-6)
I am at raised risk of premature labour; should I take long-term antibiotics?
Along with many other bacteria found in the vagina, GBS can cause infection of a baby in the womb, which can result in preterm birth, stillbirth and late miscarriage. However, these are usually caused by a variety of factors other than GBS: genetic defects, gynaecological problems, other infections, etc. If a woman has had any of these problems in the past, she should make sure these possibilities are investigated fully by a consultant obstetrician at booking (or before) regardless of whether or not she is colonised with GBS. Such complications are uncommon and GBS is a rare cause of them.
For the antibiotics tested so far, their use throughout pregnancy does not prevent preterm delivery due to any cause, including GBS. Also, the effects of long-term antibiotics on the baby during pregnancy have not been assessed; although we know that short courses of, for example, amoxycillin, seem to be exceptionally safe.
What are the signs that GBS is affecting my unborn baby?
If your pregnancy is progressing normally, then there is no reason to suspect GBS is infecting your baby. If a GBS infection is present, you’ll usually go into labour or your membranes will rupture. And that’s the time to get to hospital as quickly as you can to receive the intravenous antibiotics to give your baby the best protection possible.
Should I be induced, with the IV antibiotics starting as I’m induced?
Our medical advisers do not recommend induction for anyone as a way of combating GBS infection in babies. Carrying, or being at risk of, GBS is not a reason to be induced.
If you live a long way from the hospital or have a history of very fast labours, then induction is one way to try and ensure you get sufficient intravenous antibiotics in labour. However, induction is not without risk itself, especially before the due date. You should discuss the potential risks and benefits of an induction with your obstetrician, because they will vary dependent upon your personal circumstances.
If you need to be induced for obstetric or medical reasons, the recommended intravenous antibiotics should be started as soon as possible once labour has started or waters have broken (naturally or artificially), whichever happens first and should be repeated 4-hourly until delivery, and ideally for at least 4 hours before delivery.
Will a Caesarean prevent GBS infecting my baby?
Caesarean sections do not eliminate the risk of GBS to a baby of developing GBS infection since the bacteria can cross intact amniotic membranes to set up an infection in the baby, although they do reduce the risk.
Caesareans are not recommended as a method of preventing GBS infection in babies: they do not eliminate the risk; there are significant risks associated with a Caesarean section; and the recommended intravenous antibiotics during labour are both low risk and highly effective.
If I’m having a Caesarean, do I need antibiotics before it against GBS infection in my baby?
Caesarean sections are not recommended as a method of preventing GBS infection in the baby. They do reduce but not eliminate the risk of GBS infection to the baby, since GBS can cross intact amniotic membranes to set up an infection in the baby. There are significant risks associated with Caesarean sections; plus the recommended intravenous antibiotics during labour are highly effective and low risk.
If you are having a Caesarean section, our medical panel’s recommendations with regard to GBS are as follows:
Elective Caesareans There is no evidence to show intravenous antibiotics are indicated against GBS when a woman known to carry GBS or who previously had has a baby infected with GBS is having an elective Caesarean unless she is in labour or her membranes have ruptured. If a baby is at higher risk of developing GBS infection and the mother is having an elective Caesarean AND is in labour OR her waters have broken, she should be offered the recommended intravenous antibiotics as soon as possible after the start of labour, ideally for at least 4 hours before delivery.
The baby would only need intravenous antibiotics against GBS infection if born prematurely or if there are signs of possible infection in either the mother or the baby.
Emergency Caesareans If a woman carries GBS or has previously had a baby infected with GBS and needs an emergency Caesarean, she should be treated as for an elective Caesarean – no intravenous antibiotics are indicated against GBS unless she is in labour. If she is in labour, she should be treated as for a normal labour up until the time when an emergency Caesarean section becomes necessary, when she should be delivered immediately.
The treatment of the baby for GBS would follow the charity’s normal paediatric recommendations.
Are membrane sweeps safe for women who carry GBS?
Using a gloved finger passed through the cervix (neck of the womb) to separate the baby’s membranes from the lower part of the uterus is known as a ‘membrane sweep’. In women who are at or beyond the due date, it encourages spontaneous labour and can enable about 10% of women to avoid an artificial induction of labour.
There is currently no good evidence that membrane sweeps are harmful in women known to carry GBS. Indeed the results of trials of membrane sweeps don’t show any increase in problems caused by GBS in women having sweeps, and it is highly likely these trials would have included many women carrying GBS at the time.
However, there remains a theoretical risk that a membrane sweep might occasionally introduce GBS into the uterus, and so our medical advisory panel advises caution in using a membrane sweep for women known to carry GBS when there are other acceptable alternatives (for example, induction of labour with prostaglandin gel introduced into the vagina).
GBS and artificial rupture of membranes
Artificial rupture of membranes (AROM or amniotomy) is usually used to speed up labour, possibly shortening labour by about an hour, and usually resulting in contractions becoming stronger and more painful. We know of no contra-indications for AROM where Mum is known to carry GBS although, as it’s normally done once labour has started, you should already be receiving the 4 hourly antibiotics before AROM is done. The reason for the amniotomy should be discussed and consent should be given by the Mum before it is done.
I want a water birth
There are no known contra-indications for a woman known to carry GBS having a water birth. As for all women carrying GBS during the current pregnancy, our medical advisory panel recommends they should be offered intravenous antibiotics from the onset of labour until delivery. It is not a good idea to get the cannula (which delivers the intravenous antibiotics to the mother) wet, but this can be managed – specially designed waterproof dressings are available which keep the site sterile and dry whilst still enabling the health professional to monitor the site visually. You can read an article about waterbirths by clicking here.
I want a home birth
Our medical advisory panel’s recommendations for stopping GBS infections in newborn babies are the same for home births as for hospital births – women whose babies are at higher risk of developing GBS infection should be offered intravenous antibiotics from the start of labour until delivery.
Home births are becoming increasingly popular and, if you want a home birth with intravenous antibiotics during labour until delivery, it may be possible for your midwife to give you intravenous antibiotics prescribed for you by your GP. This is not widely available. Some areas won’t permit intravenous antibiotics to be given at home – there is a small risk that you would get a severe allergic reaction to the antibiotics (see What are the potential risks of antibiotics? above) and, obviously, there is no intensive care unit nearby. The risk is small but your health professionals may be anxious. Of course, around 25% of women having home births probably carry GBS in their vagina at delivery without knowing it. This issue needs to be discussed with your medical team.
Oral antibiotics are not recommended for women for GBS carriage during pregnancy or labour. Quite simply, there’s no evidence that they prevent GBS infections in babies. If you have set your heart on a home birth, you may wish to consider having intramuscular antibiotics as outlined in I’m worried I won’t get 4+ hours of IV antibiotics before my baby is born above, though our medical advisory panel do not recommend them in lieu of intravenous antibiotics during labour, but they may be better than nothing if that really is the only alternative.
I want to breastfeed my baby
Our medical advisory panel strongly recommends you should be encouraged to breastfeed your baby. Although there have been isolated cases describing GBS infection possibly related to breast milk contamination, the advantages of breast feeding will, in our medical advisory panel’s opinion, greatly outweigh the remote risk of transmitting GBS via breast feeding. High hygiene standards need to be maintained for all breastfeeding mothers, with the hands and nipple areas being kept clean.
The intravenous antibiotics recommended above (see Prevention) for pregnant women during labour through to delivery to protect her unborn baby from GBS infection are safe for breastfeeding mothers, although you should make sure your medical professionals know you intend to breastfeed your baby.
If you develop mastitis or a breast abscess, you should seek medical advice regarding breast-feeding.
My baby’s at higher risk of developing GBS infection – what should happen after birth?
Babies born at increased/high risk to mothers who HAVE received antibiotics for more than 2 hours before delivery should be:
- Carefully assessed by an appropriately trained Paediatrician or Advanced Neonatal Nurse Practitioner.
- If completely healthy, no antibiotics for the baby are required.
- A period of monitoring (12-24 hours) may be appropriate for those at highest risk of infection.
- Parents should be made aware of the early signs of infection and given a handout about GBS.
Babies born at increased/high risk to mothers who HAVE received antibiotics for less than 2 hours before delivery should be:
- Examined thoroughly and investigated by a Paediatrician as appropriate.
- Observed for a minimum of 12 hours, ideally 24 hours.
- If completely healthy, no antibiotics for the baby are required (antibiotics should be administered if there is any doubt).
Babies whose gestational age is less than or equal to 36 completed weeks of pregnancy and are born by Caesarean section (not in labour, no broken waters) where antibiotics were given to the mother for less than 2 hours before delivery should be:
- Examined thoroughly by a Paediatrician and a full sepsis work up done.
- Started on intravenous antibiotics unless a robust examination determines baby is completely healthy.
- Reviewed at 48 hours.
For well babies at highest risk of infection, monitoring for 12-24 hours may be appropriate and this should be undertaken as a minimum if the baby is not screened and treated for infection.
If there’s any doubt about whether an infection is present, the baby should be started on intravenous antibiotics until it is known that he/she is not infected.
What about late-onset GBS infection?
GBS infection in babies aged over 6 days is termed ‘late onset’ and comprise up to 25% of all GBS infections in babies, usually as meningitis with septicaemia. It is uncommon after a baby reaches one month old and almost unknown after age three months.
Whilst appropriate antibiotics in labour can prevent most cases of early onset GBS infection in newborn babies, these do not prevent the less common late onset GBS infections. Sadly, until a vaccine is available, there are no known ways of preventing late onset GBS infections although everyone should wash their hands properly and dry them properly before handing a baby under 3 months of age (this is good paediatric practice, not GBS specific). As with early-onset GBS infection, the mother carrying GBS late in pregnancy is a recognised risk factor for a baby developing late onset GBS infection and it may be more likely in a baby born prematurely.
Although late onset GBS infections are not common, it is important to be aware of the potential signs and symptoms and, if your baby shows any of these, please take him/her for an urgent medical review. If you have any history of GBS, mention that at the time. With prompt and appropriate treatment, most babies will make a full recovery from their GBS infection.
Warning signs of late-onset GBS infection, including meningitis – may include one or more of the following:
- poor feeding and/or vomiting; and
- impaired consciousness.
Typical symptoms of meningitis in babies, including GBS meningitis (any of these could develop but some may not be present at all) include:
- fever, which may include the hands and feet feeling cold, and/or diarrhoea;
- refusing feeds or vomiting;
- shrill or moaning cry or whimpering;
- dislike of being handled, fretful;
- tense or bulging fontanelle (soft spot on the head);
- involuntary body stiffening or jerking movements;
- floppy body;
- blank, staring or trance-like expression;
- abnormally drowsy, difficult to wake or withdrawn;
- altered breathing patterns;
- turns away from bright lights; and
- pale and/or blotchy skin.
If a baby shows signs consistent with late-onset GBS infection or meningitis, call your doctor immediately. If your doctor isn’t available, go straight to your nearest Paediatric Casualty or Emergency Department. If a baby has late-onset GBS infection or meningitis, early diagnosis and treatment are vital: delay could be fatal.
Is GBS infection linked with cow’s milk intolerance?
Cow’s milk protein intolerance is increasingly recognised in babies and is a manifestation of immune “dysregulation”. Most of the immune cells of the body are in the linings of the gut. Immature immune cells in the gut of the newborn, develop as a result of stimulation by “normal” gut flora, which live in harmony with each individual. “Dysregulation” means that the newborn immune system develops in an “unregulated” way, and so the gut does not become “tolerant” of “foreign” milk proteins such as those derived from cow’s milk. Emerging data suggests that there may be a link between antibiotic treatment of mothers and/or babies and immune dysregulation. This is not a confirmed link, just a possibility. It may be the result of exposure to antibiotics used to treat the infection, which alter the newborn baby’s gut flora, which consequently affects the generation of the “right” sort of immune responses. Alternatively, group B streptococcus may be the ‘wrong’ bacterium to stimulate normal immune development. This is an area where more research is needed.
Babies with suspected GBS infection should be given appropriate antibiotic treatment, as there could be far more serious consequences than milk intolerance, if infection is not promptly treated. Many babies who never had any antibiotic exposure either directly or via their mothers, also suffer milk protein intolerance. Babies will normally grow out of milk intolerance once the immune system matures, usually in the second 6 months of life.
GBS and Swine Flu
GBS is not a factor in the decision as to whether you should be vaccinated against swine flu, regardless of whether you know you carry GBS or not.