Group B streptococcus (GBS) can cause serious illness or death in a newborn. You might not have heard of this disease. But if you are pregnant or thinking of getting pregnant, find out how a simple screening test and antibiotic treatment can protect you and your baby.
Group B strep is a bacterium that is commonly found in vaginal and/or rectal areas. GBS can sometimes cause illness in newborn babies, pregnant women, elderly adults, and adults with chronic medical conditions like diabetes, liver disease, and cancer.
This infection is generally easy to treat in adults. But, for newborn babies, it can lead to life-threatening infections, such as sepsis (blood infection) and, rarely, meningitis (infection of the fluid and lining surrounding the brain). Babies who have had meningitis can develop long-term problems, such as hearing and/or vision loss or learning disabilities, and they can even die if the infection is left untreated.
Newborn babies become infected with GBS in three ways:
Before birth—Bacteria in the vagina can spread up the birth canal into the uterus and infect the amniotic fluid surrounding the baby. The baby becomes infected by inhaling the infected fluid into the lungs.During birth—The baby can come in contact with the bacteria in the birth canal.After birth—The baby can come in contact with the bacteria through close physical contact with the mother.
Fortunately, most babies who are exposed to the bacteria will not become infected.
GBS is present in about 25% of all healthy adult women. Not all women with the bacteria will pass it on. Factors that may increase your risk of passing GBS bacteria to your baby include:
A previous baby with GBSGBS bacteria present in urine during any trimester of the current pregnancyPositive GBS screening culture in third trimester of current pregnancy
Unknown GBS status and: Labor or rupture of the membranes (water breaking) before 37 weeks gestationA rupture of the membranes 18 hours or more before deliveryA fever during labor
Usually, the pregnant woman has no symptoms of GBS. In pregnant women, GBS infections can cause infection of the uterine lining or amniotic fluid and can lead to a miscarriage. Two forms of infection occur in newborns.
This produces illness soon after birth, usually within the first 24-48 hours, but may be up to 7 days. Problems can include
usually occurs one week to three months after birth. Medical problems associated with late-onset disease may include sepsis and meningitis. There is a chance that infants with meningitis will have long-term problems, such as
cerebral palsy, hearing loss, and developmental problems.
Newborns with GBS diseases can die if they do not receive treatment.
Symptoms for both early and late onset include:
Trouble breathingTemperature instability (high and/or low)Poor feedingIrritabilityLethargyVomiting and diarrhea
If you notice any of these symptoms in your baby (especially if you have tested positive for GBS), call the doctor right away.
Screening for GBS bacteria is simple. A swab of the of the vagina and rectum will be taken about one month before the baby is due. The sample will be sent to a lab to test for the presence of the bacteria. Test results are usually available in 24–48 hours.
The most common treatment is to give IV antibiotics during labor, hopefully at least 4 hours prior to delivery. If your baby is diagnosed with GBS, IV antibiotics will also be given. In some cases, your baby may be given antibiotics as a preventive measure.
The first thing you can do is make sure your doctor screens you for GBS before your delivery date at 35-37 weeks. If you have been identified as a GBS carrier, make sure to tell your doctor of your status when your water breaks or you arrive at the hospital in labor.
By getting screened and treated during labor (if you have GBS), you can reduce the risk of your child developing GBS.
Group B strep infection: GBS. American Pregnancy Association website. Available at: http://www.americanpregnancy.org/pregnancycomplications/groupbstrepinfection.html. Updated March 2011. Accessed October 7, 2014.
Group B streptococcal infection in infants less than 3 months old. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/. Updated My 19, 2014. Accessed October 7, 2014.
Group B streptococcus and pregnancy.
American Congress of Obstetrics and Gynecology website. Available at:
Updated August 2011. Accessed October 7, 2014.
Group B strep infection in adults. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/groupbstrep/about/adults.html. Updated November 18, 2010. Accessed October 7, 2014.
Horsely L. CDC updates guidelines for the preventions of perinatal GBS disease. Am Fam Physician. 2011;83(9):1106-1110.
American Academy of Family Physicians website. Available at:
Accessed September 13, 2012.
Meningitis. Kids Health—Nemours Foundation website. Available at: http://kidshealth.org/parent/infections/bacterial_viral/meningitis.html#cat20028. Updated April 2013. Accessed October 7, 2014.
Prevention of perinatal group B streptococcal disease--revised guidelines from CDC, 2010.
MMWR Recomm Rep. 2010;59(RR-10):1-36.
Screening and monitoring during pregnancy. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated September 19, 2014. Accessed October 7, 2014.
Last reviewed September 2014 by Michael Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © EBSCO Publishing. All rights reserved.