Group B strep infection

Between 35-37 weeks of your pregnancy your prenatal care provider will test you for Group B strep. Group B streptococcus (also called Group B strep or GBS) is a common type of bacteria that can cause infection.

Many people carry Group B strep—in fact about 25% of pregnant women are carriers.  GBS bacteria naturally live in the intestines and the urinary and genital tracts. It is not known how GBS is transmitted in adults but you can’t get it from food, water, or things you touch. An adult can’t catch it from another person or from having sex, either.  Most people do not even know they are carriers since adults usually show no signs or symptoms related to GBS.

GBS, however, can be passed to your newborn during labor and delivery and it can make your baby very sick. Babies with a GBS infection may have one or more of these illnesses:

• Meningitis, an infection of the fluid and lining around the brain

• Pneumonia, a lung infection

• Sepsis, a blood infection

According to the CDC, in the US, group B strep is the leading cause of meningitis and sepsis in a newborn’s first week of life.

There are two kinds of GBS infections:

1. Early-onset GBS: Signs like fever, trouble breathing and drowsiness start during the first 7 days of life, usually on the first day. Early-onset GBS can cause pneumonia, sepsis or meningitis. About half of all GBS infections in newborns are early-onset.

2. Late-onset GBS: Signs like coughing or congestion, trouble eating, fever, drowsiness or seizures usually start when your baby is between 7 days and 3 months old. Late-onset GBS can cause sepsis or meningitis.

The good news is that early-onset GBS infection in newborns can be prevented by a simple test. During your third trimester, your provider will take a swab of the vagina and rectum. Results are available in a day or so. This test will need to be done in each pregnancy.

If you do have GBS, then your provider will give you an antibiotic through an IV (medicine given through a tube directly into your bloodstream) during labor and delivery. Usually this is penicillin (if you are allergic to penicillin, there are other options available). Any pregnant woman who had a baby with group B strep disease in the past, or who has had a bladder (urinary tract) infection during this pregnancy caused by group B strep should also receive antibiotics during labor.

Unfortunately late-onset GBS cannot be prevented with IV antibiotics. Late-onset GBS may be due to the mother passing the bacteria to her newborn, but it may also come from another source, which is often unknown.

Treatment for babies infected with either early-onset GBS or late-onset GBS is antibiotics through an IV.

Currently researchers are testing vaccines that will help to prevent GBS infections in both mothers and their babies.

If you have any questions about this topic or other pregnancy and newborn health issues, please email the Pregnancy and Newborn Health Education Center at askus@marchofdimes.org.

Tags: antibiotics, GBS, Group B strep, prenatal care, prenatal tests