Group B Strep Infection in Newborns

Group B Streptococcus (GBS) is a type of bacteria carried by some women. These bacteria live in the gastrointestinal tract and can move into the vagina and rectum at any time. GBS can be passed on to a baby during the birthing process and can cause serious illness and even death in newborns. Group B Strep is not a sexually transmitted disease.

Group B Strep is the most common cause of two types of infection affecting newborns. These are sepsis, a blood infection, and meningitis, an infection of the lining surrounding the brain. Most newborn disease happens in the first week of life, called “early-onset” disease.

Most early-onset disease can be prevented by giving antibiotics (usually penicillin) intravenously during labor to women who test positive for Group B Strep. Testing for GBS is done through vaginal and rectal cultures taken at 35 to 37 weeks of the pregnancy. If antibiotics are given at least four hours prior to delivery, the baby will be almost 100% protected from developing early-onset disease. The risk of disease in infants of GBS positive mothers who have been partially treated (antibiotics given less than four hours prior to delivery) is not known.

Given these risks, babies born to GBS positive mothers who are not fully treated with antibiotics four hours prior to delivery will be watched closely for signs of infection in the hospital for 24 to 48 hours. The physician seeing your baby may decide to have certain blood tests performed to better evaluate the possibility of infection. Depending on each individual situation, your physician may even start antibiotics immediately.

Babies who are born to GBS positive mothers who are not fully treated need to be watched closely at home as well. If any newborn less than six weeks of age has any of the following signs, the baby’s physician should be notified immediately:

  1. Rectal temperature of 100.4º or greater.
  2. Signs of lethargy (increased sleepiness or unresponsiveness) or poor feeding.
  3. Signs of irritability (baby is crying excessively and is inconsolable).

For more information about Group B Strep, please ask your baby’s physician or refer to the Centers for

Disease Control and Prevention (CDC) website www.cdc.gov/groupbstrep.