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Home News Group B Strep: What is It? Can It Hurt My Baby?

Group B Strep: What is It? Can It Hurt My Baby?

Published: Sunday, July 1, 2007

Group B streptococcus infection (GBS) is a bacterial infection that causes one to two of every 1,000 babies born in the United States to become sick or die. It should not be confused with Group A streptococcus, which causes strep throat and, rarely, a potentially deadly destruction of flesh. Between 10 and 30 percent of pregnant women carry the GBS bacterium in the vagina or rectal area, but few babies of these women actually develop an infection.

Doctors are making progress in preventing GBS infection in newborns. In 1996, both the Centers for Disease Control and Prevention and the American College of Obstetricians and Gynecologists issued guidelines to help healthcare providers identify and treat pregnant women who are at risk of transmitting GBS to their babies. The steps they recommend usually can prevent the infection in newborns of treated women.

How do Pregnant Women Get GBS? Anyone can carry GBS, but few become sick from it. The bacterium lives in the gastrointestinal system, along with many other bacteria that are harmless to most people. The bacterium causes illness primarily in pregnant women and their babies and, occasionally, in the elderly and in adults with other illnesses such as cancer and diabetes. How do Babies Acquire GBS Infection?

There are two forms of GBS infection in infants: early and late onset. Babies with early onset infection develop symptoms within seven days of birth, most commonly within the first six hours of life. Babies with a late onset infection develop symptoms at between seven days and three months of age.

About 80 percent of all GBS infections in newborns are early onset. Early onset infections almost always are transmitted from mother to baby around the time of delivery. Late-onset infections can be contracted at delivery or acquired after birth from other sources such as inadequate hand washing by hospital personnel or from family members.

If a pregnant woman carries the GBS bacterium in her vagina or rectum at the time of labor and delivery, there is a 1-in-200 chance that her baby will become sick from GBS infection. The risk rises to 4 percent if a pregnant woman carries the bacterium and develops certain risk factors, which include the following. 

 

• Preterm labor (before 37 weeks gestation)
• Premature rupture of membranes
• Prolonged rupture of membranes
• Fever (100.4 or higher) during delivery 

 

Doctors believe that babies who become sick with GBS infection have taken the bacterium into their bodies—for example, by ingesting GBS-containing vaginal fluids during labor and delivery. Thirty to 70 percent of babies of women who carry GBS in the vagina or rectum are born with the bacterium on their skin, but most babies have no illness.

GBS Infection in a Newborn Babies with early-onset infection suffer from one or more of the following conditions: pneumonia, sepsis (blood infection) and/or meningitis (infection of the membranes surrounding the brain). Babies with late-onset infection are more likely than babies with an early-onset infection to have meningitis as their major illness.

In spite of treatment with antibiotics, about 6 percent of babies with GBS die. Of the babies who live, about 90 percent do not develop meningitis and go on to develop normally. Fifteen to 30 percent of GBS—infected babies who develop meningitis suffer lasting neurologic damage in the form of cerebral palsy, sight and hearing loss and/or mental retardation.

Important note: Doctors at the University of Tennessee Medical Center routinely screen all mothers for group B strep infection between 35 and 37 weeks of pregnancy. If your screen should be positive for GBS (meaning you have GBS) your baby will be protected during the birth process by the addition of antibiotics to intravenous fluids you will receive at that time. If you should deliver your baby prior to testing (before 37 weeks) or have other risks for GBS, you will be given IV antibiotics while in labor.

Speak with your doctor about any concerns you have during your pregnancy.

For more services, visit the Center for Women & Children’s Health.



References
American College of Obstetricians and Gynecologists (ACOG). 2007
Centers for Disease Control and Prevention. 2007.