Group B streptococcus

Key points

• Group B strep is one of the many bacteria that normally live in our bodies and which usually cause no harm.
• Screening for group B strep is not routinely offered to all pregnant women in the UK.
• If you carry group B strep, most of the time your baby will be born safely and will not develop an infection.
• However, it can rarely cause serious infection such as sepsis, pneumonia or meningitis.
• Most early-onset group B strep infections are preventable.
• If group B strep is found in your urine, vagina or rectum (bowel) during your current pregnancy, or if you have previously had a baby affected by group B strep infection, you should be offered the choice to have antibiotics in labour to reduce the small risk of this infection to your baby.
• If you carried group B strep in a previous pregnancy you will be offered the choice of a test in this pregnancy and/or antibiotics in labour.
• The risk of your baby becoming unwell with group B strep infection is increased if your baby is born preterm, if you have a temperature while you are in labour, or if your waters break before you go into labour.
• If your newborn baby develops signs of group B strep infection, they should be treated with antibiotics straight away.

Your birth, your choice

If you have any questions or worries, please speak with your doctor or midwife. We are here to support you and provide you with knowledge and information so that you can make the best decision and choices for you, your baby and your family.

To support your decision making, you can start by asking us three questions:

• What are my options?
• What are the pros and cons of each option for me?
• How do I get support to help me make a decision that is right for me?

If you have any further questions, please do not hesitate to ask us. You may find it helpful to write any questions you have down and take them to your appointments.

Introduction

Group B strep is a type of bacteria present in the bowel and rarely causes a problem, outside of pregnancy, in healthy adults.

Up to 4 out of 10 women may carry group B strep without having any symptoms. Current evidence does not support offering routine screening for group B strep in pregnancy.

If you do carry group B strep and you are pregnant, most of the time your baby will be born safely and will not develop an infection. However, rarely, group B strep can cause serious infection in a baby, which is known as early-onset neonatal group B streptococcal (EOGBS) disease. It is a recognised cause of severe neonatal infection including sepsis, pneumonia or meningitis, in around 1-2% (1 in 500) births in the UK and Ireland. If this happens, it is usually within the first seven days of birth, but it can sometimes happen later.

As group B Strep is a naturally occurring bacteria, a woman can go through phases of being and not being a carrier of the bacteria in the vagina over the course of pregnancy.

What if I had group B strep in a previous pregnancy?

If you had group B strep in a previous pregnancy, there is a 50% chance that you will have it again in this pregnancy. You can choose to have a test to see if you are still a carrier and/or choose to have antibiotics in labour.

How is group B strep detected?

There are several ways it may be detected:

• You may already know that you carry group B strep from a previous pregnancy or have had a previous baby affected by EOGBS. There is a 1 in 2 chance (50% possibility) that you will have group B strep if you have tested positive for it before. You may, however, want to be tested for it again in this pregnancy since there is also a 50% likelihood that you are not group B strep positive.
• You may have had a urine test or a vaginal swab in your current pregnancy that shows that you carry group B strep.

What could group B strep mean for my pregnancy and birth?

You will be offered the choice to have antibiotics in labour if:

• group B strep has been found in any of your previous pregnancies
• your previous baby was infected with early-onset or late-onset group B strep disease
• your midwife or doctor informs you that you have a group B strep urinary tract infection or a positive vaginal and/or rectal swab result
• you are a carrier of group B strep and your waters break at term (37+0 weeks of gestation)
• your labour starts before 37 weeks, irrespective of whether you are a carrier of group B strep or not.

Antibiotics are offered to all women who are tested for group B strep and found to carry it. The reason for this is that, while only a tiny number of babies will be severely affected, there is no way for us to know which babies will be affected, and we must therefore offer the choice of having antibiotics during labour to all women carrying the bacteria.

It is important to note that not all babies will develop an infection, so the option of antibiotics is a precautionary measure.

Please note:

• If you have group B strep confirmed from a vaginal swab, you do not need treatment at the time it is detected, and you will be offered the choice to have antibiotics in labour.
• However, if you have a confirmed group B strep urinary tract infection at any point in your pregnancy, we will offer you treatment for this with antibiotics, and you will also be offered the choice to have antibiotics in labour.

Antibiotics in labour usually means a hospital birth either on the labour ward or a stand alongside birthing unit. This is because of the equipment needed for a drip. Speak with your midwife or doctor if you are hoping to have a home birth or birth in a stand-alone birthing unit such as the Edgware Birth Centre.

Can antibiotics in labour cause any harm?

Some women may experience temporary side effects such as feeling sick or having diarrhoea. Women can be allergic to certain antibiotics and in rare cases the reaction may be severe and life-threatening (anaphylaxis). This is why we do not offer intravenous antibiotics at home or in a stand-alone birth centre. Tell your healthcare professional if you know that you are allergic to penicillin or any other medications.

Your midwife or doctor will discuss with you the benefits and risks of taking antibiotics in labour to prevent early-onset group B strep infection in your baby.

All babies are monitored after birth. If they are at an increased risk of developing EOGBS infection, they will have their observations (temperature, heart rate and respiratory rate) checked every hour for the first two hours, and then every two hours until baby is 12 hours old.

These observations can be carried out in hospital or in an alongside birth unit. These observations cannot be performed at home for 12 hours. You will also be given information about the important signs to look out for, and information about this is included below (see section: ‘What are the signs of group B strep infection in my baby?’).

Can group B strep affect my labour and birth?

Women can be allergic to certain antibiotics and in rare cases the reaction may be severe and life-threatening (anaphylaxis). This is why we do not offer intravenous antibiotics at home or in a stand-alone birth centre.

Because antibiotics are given intravenously (through a tube directly into your vein), you would need to be in a hospital setting, either in one of our alongside birth centres or on our labour ward, if you choose to have antibiotics during labour. If you have group B strep and choose to have antibiotics, you can still labour and give birth in a birthing pool.

If you are worried about your group B strep result and how this will affect where you have your baby, please do not hesitate to speak with your midwife or doctor.

Are there any other ways in which being group b strep positive may affect my pregnancy and birth?

• You are still able, should you wish, to have a membrane sweep or any form of induction of labour if you are a carrier of group B strep.
• If you are a known carrier of group B strep and have either spontaneous or an induced labour, you will be offered intravenous (through a drip) antibiotics throughout labour.
• If you have a premature birth, you will be recommended to have antibiotics in labour since your baby can be at a higher risk of infection. This is because infection is one of the most common causes of premature birth, and group B strep is one of the most common bacteria associated with the infection.
• If your waters break before 37 weeks it won’t be necessary to test for group B strep. However, you will be offered the choice to have antibiotics once labour begins (naturally or due to induction).
• After 37 weeks, if your waters have been broken from more than 18 hours, you will be offered antibiotic treatment, as this is a risk factor for group B strep.
• If you are undergoing a planned caesarean birth at term or preterm, where you are not in labour and your waters have not broken, antibiotics for group B strep is not required.

It is important to note that if you opt for antibiotics during labour, it is recommended that you are given them at least 4 hours before delivery, for the duration of the labour.

What will happen after the birth of my baby, if I have had antibiotics during labour for group B strep?

If you received antibiotics at least four hours before the birth of your baby, there will be no need for your baby to have any additional observations. If the antibiotics were given less than 4 hours before the birth, the paediatrician (baby doctor) may wish your baby to have additional observations for 12 hours after birth.

What are the signs of group B strep infection in my baby?

Most babies who develop group B strep infection become unwell in the first week of life (which is known as early-onset GBS infection), usually within 12-24 hours of birth. Although less common, late-onset group B strep infection can affect your baby up until they are three months old. Having antibiotics during labour does not prevent late-onset group B strep.

More information on late-onset group B strep infection is available Group B Strep Support website.

Babies with early-onset group B strep infection may show the following signs: 

• grunting, noisy breathing, moaning, seeming to be working hard to breathe when you look at their chest or tummy, or not breathing at all
• be very sleepy and/or unresponsive
• be crying inconsolably
• be unusually floppy
• not feeding well or not keeping milk down
• have low blood sugar*
• have a high or low temperature and/or their skin feels too hot or cold
• have changes in their skin colour (including blotchy skin)
• have an abnormally fast or slow heart rate or breathing rate
• have low blood pressure*

*identified by tests done in hospital

If you notice any of these signs or are worried about your baby, you should urgently contact your healthcare professional and also mention group B strep. If your baby has group B strep infection, early diagnosis and treatment is important as delay could be very serious or even fatal.

Can I breastfeed if I have group B strep?

Yes. Group B strep has not been shown to have any impact on breast milk, and breastfeeding has many positive benefits for you and your baby.

For breastfeeding support you can visit our Maternity service page.

I still have questions, who can I talk to?

If you have any further questions about group B strep in pregnancy, please speak to your midwife or doctor.