Why all pregnant women need to be tested for Group B streptococci (GBS)

The group B streptococcus (GBS) bacteria is usually harmless in healthy adults, but it can cause a relatively rare but very serious infection in newborns. (Group B is different from group A strep, the bacteria that causes strep throat.)Between 10 and 30 percent of pregnant women carry GBS bacteria in the vagina or rectal area, where they may pass it to their babies during labor or birth. With proper prenatal testing and treatment during labor, though, the risk is small.Without treatment, one or two out of every 200 babies born to "GBS positive" mothers would become infected with the bacteria and develop what's called early-onset GBS disease. The consequences can be very serious.

What will happen if I test positive?

A positive result means only that you carry the bacteria — not that you or your baby will definitely become ill. In fact, if you were GBS positive and didn't get treatment, your baby would have only about a 1 or 2 in 200 chance of becoming infected.Some practitioners have prescribed oral antibiotics for women who test positive to take during pregnancy — but this practice has not been found to prevent infection in newborns (the drugs won't always completely eliminate the bacteria and it can grow back later), and the CDC doesn't recommend it.So if you test positive, you'll need to have intravenous antibiotics as soon as your labor starts or your water breaks, whichever comes first. Ideally, you'll want to get started on the antibiotics at least four hours before you give birth, but if your labor is very rapid you may not have that much time. Take comfort that getting started even a couple of hours before delivery significantly lowers the risk to your baby.f you don't get your first dose four hours before the birth, you'll need to stay in the hospital for at least 48 hours after delivery so your baby can be observed for any signs of a problem. Try not to worry, though, because the chance that your baby will get sick — especially if he's full term, you don't have a fever, and your membranes aren't ruptured for long — is small.f, when you go into labor, you don't know whether you're carrying the bacteria, you'll be considered high risk and treated with antibiotics during labor if any of these situations occur.