September 23rd 2009 -
Group B streptococcus (GBS) is a type of bacterium that causes illness in newborn babies, pregnant women,
the elderly, and adults with other chronic diseases, such as diabetes or liver disease. GBS is the most common
cause of life-threatening infection in newborns. GBS can cause sepsis, meningitis and pneumonia in the
newborn. It is more common than other better-known newborn problems such as rubella, congenital syphilis,
and spina bifida. Before prevention methods were widely used, approximately 8,000 babies in the United States
would get GBS each year. One out of every 20 babies with the infection will die. Babies who do survive,
particularly those with meningitis, may have long-term problems such as hearing loss, vision loss or learning
Many people who carry GBS in their bodies do not become ill. These individuals, or "carriers," can harbor
GBS in the bowel, vagina, bladder, or throat. One out of every four or five pregnant women carries GBS in the
rectum or vagina. People who carry GBS typically do so temporarily-- that is, they do not become lifelong
carriers of the bacteria.
Only one out of every 100 or 200 babies whose mothers carry GBS will develop signs and symptoms of GBS
disease. Three-fourths of the cases of GBS disease among newborns occur in the first week of life ("early-onset
disease"), and most of these cases are apparent a few hours after birth. Sepsis, pneumonia, and meningitis are
the most common problems. Premature babies are more susceptible to GBS infection than full-term babies,
but most (75%) babies who get GBS disease are full term. GBS disease may also develop in infants one week to
several months after birth ("late-onset disease"). Meningitis is more common with late-onset GBS disease.
Only about half of those babies with late-onset GBS disease have a mother who is a GBS carrier. The source of
infection for others with late-onset GBS disease is unknown. Late-onset disease, however, is very rare.
GBS carriers can be detected during pregnancy by taking a culture swab from both the vagina and rectum of
the mother. If the physician cultures for GBS during a prenatal visit, he or she should do so late in pregnancy
(35-37 weeks' gestation); cultures collected earlier do not accurately predict whether a mother will have GBS
at the time of delivery. A positive culture result means that the mother carries GBS--not that she or her baby
will definitely become ill. The Centers for Disease Control and Prevention (CDC) recommend that women who
carry GBS should not be given oral antibiotics before labor begins because oral antibiotic treatment at this
time will not prevent GBS disease in the newborn. (An exception to this is when GBS is identified in urine
during pregnancy. The CDC recommends that GBS in the urine should be treated at the time it is diagnosed.)
Carriage of GBS in either the vagina or rectum becomes important at the time of labor and delivery when
intravascular antibiotics are effective in preventing the spread of GBS from mother to baby. Most GBS disease
in newborns can be prevented by giving pregnant women antibiotics through the vein during labor. The CDC
and the American College of Obstetricians; and Gynecologists (ACOG) recommend that any pregnant women
who previously had a baby with GBS disease, or who had a urinary tract infection caused by GBS during the
pregnancy should receive antibiotics by vein during labor. The CDC also recommends that pregnant women
who are carriers of GBS should be offered intravenous antibiotics at the time of labor or membrane rupture.
Women GBS carriers at highest risk are those with any of the following conditions:
- birth of a previous baby with GBS disease
- a urinary tract infection caused by GBS at any time during the pregnancy
- a fever during labor
- a rupture of membranes (water breaking) 18 hours or more before delivery
- premature labor or rupture of membranes (before 37 weeks gestation)
About five out of every 100 infants whose mothers are GBS carriers and who have one or more of the above
risk factors will develop GBS disease. Infants whose mothers are GBS carriers but who have no clinical risk
factors are less likely to develop GBS disease; only about one in 200 infants will get GBS disease. Those whose
mothers have clinical risk factors but who test negative for GBS are even less likely to develop GBS disease:
about one in 1,000 infants. Finally, those infants whose mothers have no risk factors and who do not culture
GBS positive have only a one in 3,000 chance of getting GBS disease.
Because women who carry GBS but do not develop any of the above complications have a relatively low risk of
delivering an infant with GBS disease, the decision to take intravenous antibiotics during labor should involve
a balance of risks and benefits. Penicillin is very effective at preventing GBS disease in the newborn and is
generally safe. A GBS carrier with none of the above conditions has the following risks:
• one in 200 chance of delivering a baby with GBS disease if antibiotics are not given
• one in 4,000 chance of delivering a baby with GBS disease if antibiotics are given
• one in 10 chance, or lower, of experiencing a mild allergic reaction to penicillin such as a rash
• one in 10,000 chance of developing a severe allergic reaction to penicillin such as anaphylaxis. Anaphylaxis
requires emergency treatment and can be life-threatening.
Whether or not you decide to be cultured by your back-up physician for GBS or decide to take intravenous
(IN.) antibiotics during labor is a matter of informed consent. The midwives do not routinely culture for GBS
nor do they give IV antibiotics during labor. If such medical testing or treatment is desired, the midwives
suggest parents discuss such options with their medical back-up physician. If further information on Group B
Strep screening or treatment would be helpful, or if you would like alternative, prophylactic treatment
recommendations, please ask the midwives.
Clients' Informed Consent or Refusal of GBS Screening
I have read the above and the midwives have answered my questions regarding testing and treatment for GBS.
I want a prenatal screening test for GBS.
I do not want a prenatal screening test for GBS
I fully accept responsibility for the results of this decision and the impact it may have on the health of my baby
Signature of Client ____________________________________ Date ______________________
Birth in the Tradition/ Mother's Keeper
Atlanta, GA 30349