Mother and Baby

Pregnancy Health A-Z: Group B Strep (GBS)

Group B streptococcus (GBS) is a bacteria many people carry, but in late pregnancy this seemingly harmless infection can pose a problem

What is it?

Group B strep is a bacteria that many women carry without knowing because it lies dormant.

‘GBS usually causes no harm, but if it's passed on from the mother to her baby during labour, it can occasionally cause serious illness for your newborn,’ says Shreelata Datta, an obstetrician at St Helier Hospital in Surrey.

Babies who are infected with GBS show symptoms within 12 hours of birth. They may be floppy and unresponsive, and may not feed well.

What are the symptoms?

There are no symptoms associated with Group B strep, which is why so many women who carry the bacteria are completely unaware. You may only become aware you carry it from a check at a routine midwife appointment.

In some cases, the infection can go without any treatment.

‘GBS can be detected during pregnancy by taking a sample by swab from your vagina and/or rectum,’ says Shreelata. ‘It can also be detected by taking a mid-stream urine sample (MSU). A urine infection caused by GBS should be treated with antibiotics.’

What can you do?

There are factors that put you into the high-risk group for group B strep.

These include if the bacteria has shown up during a previous labour, if it shows up from a urine sample approaching labour or if you have gone into labour prematurely before 37 weeks. If you are considered high risk, your doctor will give you antibiotics via a drip in your arm to reduce the risk of your baby developing the infection.

These are given from the start of your labour or from when your waters break, right up to your baby's birth.

See your GP...

If you experience pain when urinating, or you’re suffering from abnormal vaginal discharge during your pregnancy.

‘Babies come into contact with GBS during labour or during birth,’ says Shreelata. ‘The vast majority of babies, however, are not harmed.’

If your baby is found to be suffering from GBS, he will be treated with penicillin.

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