Group B streptococcus, or group B strep for short, is a certain kind of bacteria (germ) that lives in the vaginal or rectal areas of about 25% of healthy pregnant women. A woman who has group B strep is said to be "colonized" with this germ. If you are colonized with group B strep, your baby can become infected with these germs while being born and can get sick. There is less than a 1% chance that this will happen, but because group B strep infection is so dangerous for babies, it's important to find out if you're colonized while you're pregnant.
Your doctor can do a skin culture to see if you have group B strep on your skin. This is done by taking a bit of your skin and sending it to a lab to see if the strep bacteria grow. Your doctor can also do a test on your vagina and rectum to see if it is inside your body. The test is like a Pap smear.
Your doctor may have you take antibiotic pills during pregnancy until you give birth. Then, when you're in labor, you can also take antibiotics intravenously (through an IV) to kill the germs. If you take antibiotics while you're in labor, the chances very high that your baby won't get this infection.
Carrying the bacteria in your body when you're pregnant doesn't usually make you sick. In some cases, though, group B strep germs can multiply inside your body and can cause serious infection. When you are pregnant and have group B strep, your baby could get the germs from you during delivery and get sick. Infected babies need treatment. Your baby will be kept in the hospital some extra days for close watching (observation) if your doctor thinks the baby is infected with strep. Blood tests will be done to see if your baby has group B strep. If your baby has this germ, the doctor will give the baby antibiotics.
Written by familydoctor.org editorial staff