Group B Streptococcus (GBS)

GBS is a type of bacteria found in the vaginas of up to 30% of women. Rectal carriage of GBS provides a reservoir for recurrent vaginal colonization and may contribute to urinary tract infections with GBS.

Routine antenatal treatment with antibiotics is not indicated because fluctuations in bacterial numbers make it impossible to completely eradicate the bacteria and recolonization is very common.

GBS usually does not cause any problems in the mothers, but during labor and delivery, it can pass to the baby and is the leading cause of infections and meningitis in newborns.

Approximately 1-2% of babies born to mothers with GBS will show signs of illness. GBS infections can present as either early or late infections.

Early infections occur within the first seven days, and most commonly within the first 20 hours. Symptoms include difficulty with breathing, signs of infection, fever, irritability and failure to feed and thrive. The mortality rate is from 15-50% for all symptomatic babies.

Late onset infection presents from 1-12 weeks of age, with three weeks being the most common time frame. Approximately 1/2 - 1% of babies will be affected and the symptoms are similar to early onset GBS. The mortality rate is from 2-6% of all infected babies. However, 25-50% of the remaining infants who had meningitis may have long lasting neurological problems, such as speech/language delays, muscle spasticity, visual disturbances and even loss, hearing difficulties and seizures.

During your prenatal care, we will test all pregnant women for GBS at approximately 36 weeks. This involves taking a culture from the lower vagina and rectum with a Q-tip. If the culture results are positive, you will be given antibiotics during labor.

Sometimes we may consider treatment in women at the time of labor even with unknown or negative test results. These reasons may include but are not limited to the following:

• Labor less than 37 weeks
• Preterm, premature rupture of membranes (before 37 weeks)
• Prolonged rupture of membranes (more than 18 hours)
• Prior child with GBS infection
• Fever during labor

Remember that GBS is common in pregnant women, and very few babies actually even become ill. We know that certain risk factors increase a baby's chance of becoming infected (see above). If there is a positive result or risk factor, we will treat you with antibiotics, and your baby will more than likely do very well. Occasionally these babies are monitored more closely by the nursery staff at Potomac Hospital in order to assure the best outcome.