How is group B strep infection treated during pregnancy?

To help protect their babies from group B strep infection, pregnant women who test positive for group B strep in the current pregnancy should receive antibiotics (medicine) through the intravenous vein (IV) during labor. Also, pregnant women who have group B strep detected in their urine during the current pregnancy or who had a previous infant with group B strep disease should receive antibiotics during labor; they do not need to be screened at 35-37 weeks because they should receive antibiotics regardless of the screening result. Pregnant women who do not know whether or not they are group B strep positive when labor starts should be given antibiotics if they have:

• labor starting at less than 37 weeks (preterm labor);
• prolonged membrane rupture (water breaking 18 or more hours before delivery); or
• fever during labor.

Antibiotics help to kill some of the group B strep bacteria that are dangerous to the baby during birth. The antibiotics help during labor only -- they can't be taken before labor, because the bacteria can grow back quickly. Penicillin is the most common antibiotic that is given. For women who are severely allergic to penicillin, there are other antibiotics that can be given. Women should tell their doctor or nurse about any allergies during a checkup and try to make a plan for delivery. When women get to the hospital, they should remind their doctor if they are allergic to any medicines.

Penicillin is very safe and effective at preventing group B strep disease in newborns. There can be side effects from penicillin for the woman, including a mild reaction to penicillin (about a 10% chance). There is a rare chance (about 1 in 10,000) of the mother having a severe allergic reaction that requires emergency treatment.

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Group B strep infection, which is a growth of streptococcal bacteria in the vagina, is usually treated with intravenous antibiotics when the mother is in labor in the hospital. There are several antibiotics approved for this purpose. Group B strep is treated in order to decrease the risk of infections in the newborn, which can include infection of the blood, pneumonia and meningitis. Testing for group B strep is usually done by collecting a specimen with a sterile swab from the mother's vagina and rectum between weeks 35 and 37 of pregnancy. About 25% of pregnant women carry the bacteria.