Hi Jodi,

It's a vaginal swab they do to test for the presence of Group B Strep, which can cause serious problems for babies if they catch it on the way through. It's a very common bacteria which many people have in them without having any problems, and at different times can be active and inactive.

If you have an active case close to delivery, they will recommend (but can't force you to have) antibiotics during labour, to help prevent the baby from picking up GBS.

HTH