Consultant Leonie Penna says:
GBS stands for group B streptococcus. This is a bacterium that occurs naturally in the back passage of 50% of adults. In about 25% of women it also lives in the vagina. It’s not sexually transmitted or a sign of poor hygiene. It causes no symptoms and doesn’t need treatment.
The problem with GBS is that it can pass to the baby during labour and cause pneumonia or, in serious cases, meningitis. The chance of the baby picking up an infection is about 1 in 500 and if that happens there’s a 10% chance it will be fatal. Giving penicillin to the mother intravenously during labour is known to significantly reduce the risk of the baby contracting GBS infection, but since intravenous antibiotics are difficult to arrange at home, a hospital birth is usually advised.
You can say you don’t want antibiotics, in which case the hospital would normally suggest your baby is closely monitored after birth to spot signs of infection. It’s probably best to see your doctor to discuss the options available at your local maternity unit.