Antibiotics for GBS in labour

The maternity team recommends this preventive treatment when screening or pregnancy history shows that the baby may be exposed. Treatment is normally started after labour begins or the waters break because the aim is protection around birth, not long-term removal of GBS carriage.

Group B streptococcus, or GBS, is a bacterium that can live in the bowel or genital tract without causing symptoms. A positive screening result does not mean the pregnant person is unwell, but bacteria can sometimes reach the baby during birth and cause serious newborn infection.

Antibiotics before labour are not routinely used simply to clear carriage because GBS can return. A urinary infection caused by GBS is a separate issue and may need treatment when it is diagnosed as well as a plan for labour.

Make sure the maternity team knows about the GBS result and any previous baby affected by GBS infection. Contact the maternity unit when labour starts or the waters break and follow its instructions about when to attend. The antibiotic is given through a cannula, with repeat dosing directed by the clinical team while labour continues.

Report any previous reaction to penicillin, cephalosporins or another antibiotic, describing what happened rather than only naming an allergy. This helps clinicians choose an appropriate alternative when needed. Keep the result or maternity record accessible if you attend a different hospital.

Call the maternity unit promptly if your waters break, contractions begin, fetal movement is reduced, you have vaginal bleeding, or you feel feverish or unwell. These signs need obstetric guidance regardless of whether the GBS result is positive.

During an antibiotic infusion, tell staff immediately about itching, hives, swelling, wheezing, breathing difficulty, dizziness or sudden vomiting. After birth, the newborn team decides whether observation or tests are needed using the labour history, the baby's condition and the antibiotics received.

Ask what event should prompt you to travel to the maternity unit, which antibiotic is planned, how a documented allergy changes that plan, and what happens if birth progresses before treatment can be completed. You can also ask how the baby will be observed after delivery.