Group B Strep
What is Group B Strep?
The term Group B Strep (or GBS) refers to the bacteria group B streptococcus. About 1/3 of all healthy adults have the group B streptococcus bacteria living in their digestive system, including 10-35% of pregnant women. Because GBS can live in the human body without making the human ill, persons who have the bacteria but show no signs of infection are said to be colonized. A person who is made ill by the bacteria is said to have Group B Strep disease.
Why is Group B Strep a labor challenge?
GBS is a normal intestinal bacteria and generally causes the human no problems. However, it is possible for the bacteria to migrate to the vaginal area of a pregnant woman. This would not make the woman sick, but does make it possible for the baby to come into contact with the bacteria while being born. This contact causes the risk that the baby will contract Group B Strep disease during birth.
1 in 100 or 1 in 200 colonized women will give birth to babies who have contracted Group B Strep disease. According to the Group B Strep association, approximately 8,000 babies in the United States contract Group B Strep disease each year. About one quarter of all newborns infected are premature. Approximately 1 in 5 infected babies will die. GBS is the leading cause of newborn infection. Some babies that survive may struggle with medical problems such as hearing or vision loss, physical or learning disabilities and cerebral palsy.
Antibiotics during pregnancy can end the Group B strep colonization, but the results can only be considered temporary. Because the Group B Strep is able to migrate, the infection can come back. For this reason, antibiotics used during pregnancy should be timed to end as close to labor starting as possible.
If the bacteria is present, the challenge in labor is to prevent the baby from contracting the bacteria. This is generally done by giving the colonized mother IV antibiotics during labor, though some care givers will only offer after the bag of waters has been broken for more than 18 hours (when the risk for contracting GBS increases). Antibiotics during labor does help to decrease the risk the bacteria will infect the baby. Being hooked up to an IV pole is cumbersome and may be uncomfortable in labor, but should not prevent you from giving birth naturally.
There is disagreement about how to determine which women should receive antibiotics. One theory says to make testing routine during pregnancy and offer antibiotics to women who test positive, however there is not enough evidence to recommend that all women be screened for Group B Strep. Also, since Group B strep comes and goes, results from a few weeks before labor begins may not be reflective of what is or is not present when labor starts. Another theory says to test all women at the onset of labor with a rapid test, however testing capabilities are not quite ready for this to become routine. A third theory says to offer antibiotics only to those women who have risk factors such as broken waters for a time or a history of Group B Strep infection.
The exception would be that some caregivers recommend induction for colonized women whose bag of waters is broken if labor has not started. Because of the risk of infection when the bag of waters is broken, your options for medically inducing labor will probably be limited to pitocin.
Use good health practices to prevent yourself from becoming colonized. Eat a healthy diet to keep the digestive flora in proper proportions. Be sure to only wipe from the front to the back to help prevent infections.
Avoid cervical checks and internal devices which increase the risk for infection.
Avoid amniotomy (artificial rupture of the membranes).
Remember that the increased risk does not occur until the bag of waters has been broken for 18 hours.
Things to discuss with your caregiver:
There are two recommended strategies for preventing GBS. One is to screen every woman at 35-37 weeks pregnancy and offer antibiotics to colonized women. The other is to screen no one, but to offer antibiotics to women who have risk factors such as preterm labor, membranes ruptured for 18 hours or more or a previous baby with GBS disease. Which strategy does your caregiver use?
The American College of Nurse Midwives has suggested using oral antibiotics when the membranes are ruptured for more than 18 hours but labor has not started; switching to IV antibiotics when labor begins. Is this a possibility in your case?
According to the CDC, either strategy is effective at reducing newborn infection rates by 70 to 85%. However, that still leaves 15 - 30% of babies who will be infected. If your baby is one of the 15-30%, what can you expect to happen at the hospital? What will be the treatment? Will your baby need to spend time in the nursery?
According to the research of Henci Goer, "there is a clear connection between ruptured membranes, number of vaginal exams, use of internal monitoring devices, time and infection." Because of the link between vaginal exams and internal monitors to increased infection rates, your caregiver may recommend the fewest possible vaginal exams and to use only external monitoring equipment.
Goer, Henci. The Thinking Woman's Guide to a Better Birth. 1999. New York: The Berkley Publishing Group.
Prevention of Perinatal Group B Streptococcal Disease. MMWR August 16, 2002 / 51(RR11);1-22.
Enkin, Keirse, Nilson, Crowther, Duley, Hodnett and Hofmeyr. A guide to effective care in pregnancy and childbirth Third Edition. 2000. Oxford: Oxford University Press.