Positive for strep B in pregnancy: what it means

Group B Streptococcus, often called GBS, can live normally in the bowel or vagina without causing illness. A positive pregnancy swab does not mean you are unwell or that you caused a problem. It identifies a possible source of exposure for a baby during birth.

The result is used to plan care around labour. It does not usually change ordinary pregnancy activities, and it is separate from tests for sexually transmitted infections. Your team should tell you how the result is recorded and whether any earlier history changes the plan.

Tell the hospital or midwife caring for you that you have a positive result when labour begins or your waters break. Keep the result in your maternity notes and ask when intravenous antibiotics will be offered. The medicine is given during labour so it is present around the time of birth; antibiotics taken earlier in pregnancy do not replace this plan.

Ask what to do if labour starts quickly or you are transferred between units. After birth, the newborn team may observe your baby and check for signs of infection according to the circumstances.

Call your maternity unit if your waters break, contractions become regular, you have vaginal bleeding, or you feel unwell. A positive GBS result is not itself an emergency, but the team needs to know promptly when labour or membrane rupture begins so birth care can be arranged.

Ask: Where is my result recorded? When should I call? Which antibiotic will be offered? What if labour progresses quickly? How will my baby be observed after birth?